Rapid purification and properties of protein kinase C from bovine adrenal medulla

Protein kinase C was purified from bovine adrenal medulla using a rapid procedure which resulted in an approximate 1500-fold increase in specific activity. The characteristics of the enzyme are reported and for the first time it is possible to compare the effects of TPA on secretion from intact and permeabilized cells with the effect of TPA on protein kinase C purified from the same secretory tissue.     

Sustentacular cells in the fetal human adrenal medulla are immunoreactive with antibodies to brain S-100 protein

Summary Adrenal glands of human fetuses were investigated by means of an immunohistochemical method with the use of an anti-S-100 serum. S-100-immunoreactivity was recognized in sustentacular cells located among the chromaffin cells. A characteristic circular arrangement of the immunostained cells was found in the central region of the adrenal glands. It surrounded aggregations of non-argyrophilic, small, round cells, which were identified as the remaining sympathoblasts (primitive sympathetic cells).     

Short- and long-term effects of vinblastine on the rat adrenal medulla

Summary The effects of a single high dose (10mg/kg) of vinblastine (vb) sulfate (Velbe, Lilly) on the ultrastructure, catecholamine (CA) content and activity of CA-synthesizing enzymes of the rat adrenal medulla were studied for up to 120h after intravenous injection of the drug.By 1 h, microtubules were virtually absent from chromaffin cells and preganglionic cholinergic axons, and typical paracrystals had appeared inside the nerve fibers. By 16h microtubules were completely reconstituted and paracrystals had disappeared. From 16h onwards, there was an increasing depletion of storage granules from adrenaline (A) — producing cells, which coincided with biochemical determinations showing a reduction of adrenal A to about 40 % of control levels by 48 h, with noradrenaline (NA) remaining in the range of controls. Both A- and NA-storing cells showed an extensive proliferation of the rough endoplasmic reticulum (ER). Vb caused a marked increase in tyrosine hydroxylase (TH; +113%) and dopamine -hydroxylase (DBH; +82%) activities after 48 h. Splanchnicotomy completely abolished the vb-mediated increase in TH and DBH activities. A smaller increase (+ 47 %) in enzyme activity was observed with phenylethanolamine N-methyltransferase (PNMT). Vb (10^–5M) had no apparent effect on granule content and the amount of rough ER in chromaffin cells, which were cultured for 48 h.The results demonstrate that a single high dose of vb has relatively little short-term effects on the rat adrenal medulla, but causes drastic long-term changes in CA-content and enzyme activities that are mediated by the preganglionic nerves. These changes could be interpreted as an effort to compensate for a loss of CA-stores in peripheral adrenergic nerves (cf. Cheney et al., 1973). The differential long-term effect of vb on adrenal NA and A might be due to the lower induction of PNMT as compared to TH and DBH activities and/or to a preferential release of A versus NA, which may occur at high frequencies of stimulation of the splanchnic nerves.Supported by grants from the Deutsche ForschungsgemeinschaftDedicated to Professor G. Petry in honor of his 65th birthday     

Mouse adrenal chromaffin cells can transform to neuron-like cholinergic phenotypes after being grafted into the brain

The development of neuron-like cholinergic immunophenotypes by adrenal chromaffin cells was studied in 10-week-old mouse adrenal medullary grafts. Fragments of chromaffin tissue were implanted into mouse hippocampus, and antibodies specific for neurofilaments (NF), neuron-specific enolase (NSE), choline acetyltransferase (ChAT), acetylcholinesterase (AChE), and phenylethanolamine-N-methyltransferase (PNMT) were applied to the grafts. Adrenal medulla grafts survived well and most of the transplanted cells were either round or polygonal. A minority of chromaffin cells elaborated an intermediate or sympathetic neuron phenotype. Chromaffin cells showed pronounced immunoreactivity for NSE in their perikarya and axon-like processes: immunoreactivity for NF was only found in a few processes. In adjacent immunohistochemically stained sections, the transplanted cells stained for ChAT and AChE. At the electron-microscope level, the immunohistochemical reactions for the two acetylcholine-related enzymes were mainly located on the endoplasmic reticulum and in cell processes. Immunoreactivity for PNMT was found to decline in transplanted chromaffin cells below that of normal adrenal medulla. These observations suggest that, in adrenal medullary grafts implanted into the hippocampus, chromaffin cells are endowed with neuron-like cholinergic immunophenotypes.     

Ultrastructural radioautography of the incorporation of tritiated leucine by the rat adrenal medulla in vivo

Summary Sections of tissues from the adrenal medullae of young rats were subjected to radioautography after a single intravenous injection of L-leucine 4,5 ³H to identify the sites of synthesis and follow the migration of newly-formed proteins in both adrenaline-storing (A) and noradrenaline-storing (N) cells. As early as 2 min after injection of leucine ³H, the label was highest in the rough endoplasmic reticulum (RER) of A and N cells, suggesting that cisternal ribosomes are sites of protein synthesis. By 5 and 10 min, much of the label had migrated from the RER into the Golgi complex of both cell types. Some label was already present over the secretory granule matrix (chromogranins) by 2 min but the peak was reached at 1 h in both A and N cells. By 4 h, the label over the secretory granules had diminished, indicating a release of newly-synthetized chromogranins outside the cells. The label over the hyaloplasm was relatively high at 2 min but it decreased rapidly to low levels. In contrast, the label over the cell surface continually increased to reach the highest levels among all organelles at 4 h in both cell types. The pattern of increment of the label over the cell surface suggests that the newly-formed proteins of these sites are also synthetized in the RER, pass through the Golgi complex and are transported in the hyaloplasm, before reaching the surface of A and N cells.Supported in part by the Quebec Heart Foundation, the Medical Research Council of Canada (Grant MT-1973), the J.-L. Levesque Foundation, the Ministry of Education of Quebec (Formation de Chercheurs et Action Concertée) and the Fond de l'Université de Montréal (Cafir)     

Differentiation and transdifferentiation of adrenal chromaffin cells of the guinea-pig

Summary Expiants of adrenal medullary tissue taken from newborn guinea pigs were grown in culture for up to two weeks. The explants exhibited sparse outgrowth of neurite-like processes, in contrast to adrenal medullae taken from young postnatal rats or adult guinea pigs that were (i) grown under identical conditions (Unsicker and Chamley 1977) or (ii) transplanted to the anterior chamber of the eye (Unsicker et al. 1981), respectively. Nerve growth factor (10–100 ng/ml, 2.5S NGF) did not enhance formation of processes. However, electron-microscopic investigations revealed the presence of numerous processes within the explants, which extended from chromaffin cells and were characterized by longitudinally oriented cytoskeletal structures, various populations of clear and dense-cored vesicles, varicosities and growth cones. Chromaffin cell bodies largely resembled their in situ-counterparts, but had fewer and smaller storage vesicles than controls.The results are discussed in light of recent findings regarding the potency of NGF and NGF-like growth factors to induce neuronal transdifferentiation of adrenal chromaffin cells.Supported by grants from the Deutsche Forschungsgemeinschaft (SFB 103 and Un 34/6)     

Modulation of catecholamine release by endogenous adenosine in the rat adrenal medulla

Adenosine was shown to inhibit norepinephrine (NE) release from sympathetic nerve endings. The purpose of this study was to examine whether endogenous adenosine restrains NE and epinephrine release from the adrenal medulla. The effects of an adenosine receptor antagonist, 1,3-dipropyl-8-(p-sulfophenyl) xanthine (DPSPX), on epinephrine and NE release induced by intravenous administration of insulin in conscious rats were examined. Plasma catecholamines were measured by HPLC with an electrochemical detector. DPSPX significantly increased plasma catecholamine in both control rats and rats treated with insulin. The effect of DPSPX on plasma catecholamine was significantly greater in rats treated with insulin. Additional experiments were performed in adrenalectomized rats to investigate the contribution of the adrenal medulla to the effect of DPSPX on plasma catecholamine. The effect of DPSPX and insulin on epinephrine in adrenalectomized rats was significantly reduced compared with that of the controls. Finally, we tested whether endogenous adenosine restrains catecholamine secretion partially through inhibiting the renin-angiotensin system. The effect of DPSPX on plasma catecholamine in rats pretreated with captopril (an angiotensin-converting enzyme inhibitor) was reduced. These results demonstrate that under basal physiological conditions, endogenous adenosine tonically inhibits catecholamine secretion from the adrenal medulla, and this effect is augmented when the sympathetic system is stimulated. The effect of endogenous adenosine on catecholamine secretion from the adrenal medulla is achieved partially through the inhibitory effect of adenosine on the renin-angiotensin system.     

Catecholamine-storing cells in the adrenal medulla of the pre- and postnatal rat

Summary The development of the rat adrenal medulla was studied at the ultrastructural level with particular emphasis placed on early discrimination of different catecholamine-storing cells. The first granule-containing cells, phaeochromoblasts, were seen at day 15 of gestation migrating into the anlage of the cortex. These cells were characterized by a few small granules (80–120 nm in diameter) and a high nuclear to cytoplasmic ratio. Presumably due to differentiation into chromaffin cells, they were no longer present after the eighth postnatal day. Maturation of phaeochromoblasts was indicated by an increase in number and size of their storage granules and a decrease in the nuclear to cytoplasmic ratio. Noradrenaline and adrenaline cell types were first clearly discernible at day 21 of gestation. Another cell type, a giant cell, was also recognized at this stage. In the adult animal, noradrenaline, two morphologically different types of adrenaline, and small granule-containing cells were observed.By applying acetylcholinesterase histochemistry, it was found that at day 17 of gestation a small population of granule-storing cells showed strong positive staining in the endoplasmic reticulum. In the adult animal this cell type was further characterized by small-storage granules. Other chromaffin cells began to show weak staining within the endoplasmic reticulum at day 19 of gestation. This staining appeared more frequently within adrenaline than noradrenaline cells. However, even in the adult animal many cells of both types were completely negative.It is concluded that acetylcholinesterase histochemistry is a useful method for early discrimination of small granule-containing cells in the developing rat adrenal medulla.Supported by grants from the Deutsche Forschungsgemeinschaft     

Growth characteristics of postnatal rat adrenal medulla in culture

Explants and enzyme-dispersed cells of adrenal medulla from 10-12 day old rats were studied in culture for up to 3 weeks. Adrenomedullary chromaffin cells, nerve cells and satellite cells were clearly discernible. The nerve cells were few in number and did not show catecholaminespecific fluorescence. Chromaffin cells stored catecholamines, as judged by the Falck and Hillarp method, in varying amounts decreasing with age of the cultures and the distance from the explants. Exocytosis profiles observed with the electron microscope suggested that cultured chromaffin cells also released catecholamines. Moreover, the cells formed processes and frequently migrated into the outgrowth. After 6 days in culture, the great majority of chromaffin cells stored noradrenaline as revealed by electron microscopy with few adrenaline-storing cells being visible. Granular vesicles (approximately 80-240 nm in diameter) with cores of different electron densities were occasionally present in the same cell suggesting the occurrence of mixtures of primary and secondary amines. Apart from "chromaffin" granules, small clear and dense-cored vesicles (approximately 40-60 nm) were found both in the somata and cell processes. Chromaffin cells and their processes were often closely apposed and occasionally formed specialized attachment zones. As a whole, chromaffin cells in culture resembled small granule-containing cells in sympathetic ganglia. 0.5 mM dbcAMP prevented dedifferentiation of chromaffin cells as judged by the lack of processes, the size and amount of "chromaffin" granules and the high number of adrenaline-storing cells present after 6 days in culture. NGF caused a striking increase in the number of axons growing out from explants.     

Purification and characterization of an inhibitor protein with cytochalasin-like acitvity from bovine adrenal medulla

A protein preparation with cytochalasin-like activity has been obtained from bovine adrenal medulla. Analysis by electrophoresis in SDS-polyacrylamide gels and chromatography in a Sephacryl S-200 column indicated that the inhibitor activity coincided with a 90 000 dalton polypeptide. The inhibitor decreased high-affinity binding of [³H]cytochalasin B to actin nuclei, apparently by competing with the drug for thesame binding site. At substoichometric levels, the inhibitor had a potent effect on actin filament elongation and on actin-dependent gelation of cell extracts in vitro. These results suggest that the inhibitor may be involved in the control of actin filament assembly and interaction in the adrenal medulla.     

Autoradiographic localization of strychnine-sensitive glycine receptor in bovine adrenal medulla

The presence of an uptake system and a functional glycine receptor in adrenal medulla chromaffin cells was investigated using an autoradiographic technique in adrenal gland slices. Specific³[H]-glycine binding was observed in both adrenal cortex and medulla slices, while only specific binding of [³H]strychnine was seen only in chromaffin cells and was not associated with cortical cells. [³H]Glycine binding sites in the cortex are apparently different from those of [³H]strychnine binding sites in the medulla since excess strychnine does not displace [³H]glycine from adrenal cortex but does so from medulla. This difference supports biochemical evidence for glycine transport into medulla cells and glycine receptor sites on the chromaffin cell membrane.     

Fasudil attenuates sympathetic nervous activity in the adrenal medulla of spontaneously hypertensive rats

We investigated the effects of fasudil, a Rho kinase inhibitor, on hypertension in spontaneously hypertensive rats and on the catecholamine synthetic pathway. Ten-week-old male SHR and Wistar-Kyoto rats were administered fasudil (10 mg/kg/day s.c.) for 4 days. Systolic blood pressure was measured using the tail-cuff method. Catecholamine levels were measured with high-performance liquid chromatography-ECD methods. Tyrosine hydroxylase protein levels were measured in Western blot analysis. The tyrosine hydroxylase mRNA level was measured using real-time PCR methods. Fasudil significantly decreased systolic blood pressure in spontaneously hypertensive rats, but not in Wistar-Kyoto rats. Fasudil also significantly decreased catecholamine, tyrosine hydroxylase protein, and tyrosine hydroxylase mRNA levels in the adrenal medulla of spontaneously hypertensive rats. These results suggest that the depressor effects of fasudil on hypertension in spontaneously hypertensive rats may be related to inhibition of the catecholamine synthetic pathway.     

Role of proto-oncogenes in the regulation of proenkephalin mRNA expression induced by repeated nicotine injections in rat adrenal medulla

We have studied the effect of repeated systemic administrations of nicotine (3 mg/kg) at 30 min intervals on proenkephalin (proENK) mRNA level in rat adrenal gland. Northern blot analysis has shown that proENK mRNA expression was enhanced by repeated nicotine administrations. Additionally, repeated administrations of nicotine transiently induced the c-fos and c-jun mRNA levels after the first-third nicotine administration, and the c-fos and c-jun mRNA levels were returned to the basal level after the seventh administration of nicotine. c-Fos, c-Jun and Fra-2 protein levels were persistently increased until the seventh administration. The repeated nicotine administrations also elevated phospho-CREB without altering total CREB level in all tested groups. Immunohistochemical analysis showed that the increase of c-Fos and c-Jun proteins by repeated nicotine administrations is mostly medulla specific, while Fra-2 immuno reactivity was shown both in medulla and cortex. The repeated nicotine administrations enhanced the AP-1 and ENKCRE-2 DNA binding activities. Furthermore, the cross-competition studies revealed that the AP-1 proteins, rather than CREB, actively bind to ENKCRE-2 DNA domain. These results suggest that proENK mRNA expression induced by repeated nicotine administrations may be mediated by AP-1 proteins, such as c-Fos, c-Jun and Fra-2 rather than CREB via interacting to the ENKCRE-2 DNA binding domain in rat adrenal medulla.     

Chemical coding of neurons in the myenteric plexus and external muscle of the small and large intestine of the mouse

Immunohistochemical techniques were used to examine the presence and co-localisation of a range of putative neurotransmitters and other neuronal markers in the myenteric plexus of the small and large intestine of the mouse. Distinct sub-populations of myenteric neurons were identified, based on the combinations of substances they contained and the distribution of their fibres. In the small intestine, there were two major classes of circular muscle motor neurons; one class was characterised by the presence of nitric oxide synthase, vasoactive intestinal peptide plus neuropeptide Y (NOS/VIP/NPY), and the second class contained calretinin plus substance P (CalR/SP). There were seven classes of neurons that innervated myenteric ganglia; these contained NOS, VIP, NOS/VIP, NPY, CalR/calbindin (CalB), SP or 5-HT. In the large intestine, there were five major classes of motor neurons that contained NOS, NOS/VIP, GABA, SP, or CalR/SP, and seven major classes of neurons that innervated myenteric ganglia and contained NOS, VIP, CalR/CalB, CalR, SP, GABA or 5-HT. Although some aspects of the patterns of co-localisation are similar to those in other species, this study re-inforces recent analyses that indicate significant species differences in neurochemical patterns in the enteric neurons of different species. Received: 28 August 1995 / Accepted: 30 November 1995     

Subcellular localization of prostaglandin E2 binding sites in bovine adrenal medulla

Prostaglandins E₁ and E₂ are specifically bound by particulate fractions from bovine adrenal medulla. The subcellular localization of these binding sites has been investigated by comparing their distribution in subcellular fractions obtained by differential and gradient centrifugation to those of marker enzymes for various organelles. Prostaglandin E₂ binding sites were purified about 16-fold with respect to the homogenate in a fraction which was highly enriched in plasma membranes on the basis of the activities of the marker enzymes acetylcholinesterase and calcium-dependent ATPase, which were both purified by about 12-fold in this fraction. The plasma membrane fraction contained relatively low activities of marker enzymes for mitochondria (monoamine oxidase), lysosomes (acid phosphatase), endoplasmic reticulum (glucose-6-phosphatase), Golgi (galactosyl transferase) and chromaffin granule membranes (dopamine β-hydroxylase). The only other fractions enriched in prostaglandin E₂ binding sites were those for the endoplasmic reticulum and the Golgi, in which the binding sites were purified about 4-fold and 7-fold, respectively. This is probably due mainly to contamination with plasma membranes, since calcium-dependent ATPase and acetylcholinesterase were each purified to a similar extent in these two fractions. These data suggest that the high-affinity prostaglandin E₂ binding sites of the adrenal medulla are localized primarily on the plasma membranes of the medullary cells.     

Central angiotensin II increases biosynthesis of tyrosine hydroxylase in the rat adrenal medulla

Angiotensin II acting centrally contributes to the regulation of blood pressure and water intake and stimulates the release of catecholamines from the adrenal medulla. We hypothesized that the central angiotensin II is one mediator of biosynthesis of catecholamines in the adrenal medulla. Rats were administered i.c.v. angiotensin II or saline, and TH mRNA and protein levels in adrenal medulla were measured 1 or 3 h later. Angiotensin II did not change TH mRNA or protein 1 h later. However, by 3 h, angiotensin II increased TH mRNA and protein levels. Centrally administered angiotensin II elevates TH mRNA expression and protein levels in the adrenal medulla. In conclusion, one component of central angiotensin II elevation of blood pressure may be the result of increased catecholamine synthesis in the adrenal gland and elevated TH synthesis represents one underlying mechanism.     

Immunohistochemical and biochemical study on the development of the noradrenaline- and adrenaline-storing cells of the adrenal medulla of the rat

Summary The pre- and postnatal development of the adrenal medulla was examined in the rat by immunohistochemistry and by assay of catecholamines. Immunohistochemistry involved the use of antibodies to noradrenaline (NA), adrenaline (A) and the biosynthesizing enzymes dopamine -hydroxylase (DBH) and phenylethanolamine N-methyltransferase (PNMT). Adrenal glands were obtained from animals from the 16th day of gestation to the 7th postnatal day at daily intervals, and at the 14th postnatal day, and from adult rats. Tissues were fixed in ice-cold, 4% paraformaldehyde, buffered at pH 7.3. Cryostat sections (7 m) were stained with the indirect immunofluorescence technique. Adrenals from the same developmental stages were assayed for the presence of DA (dopamine), NA and A by ion-pair reversed-phase liquid chromatography with electrochemical detection.In adult adrenals the majority of the medullary cells (approximately 80%) were highly immunoreactive to A and moderately immunoreactive to NA. They also showed immunoreactivity to both DBH and PNMT, i.e., they are synthesizing and storing A. The remaining cell clusters were only stained by antibodies to DBH and NA (NA-synthesizing and -storing cells). These findings correlate well with the relative concentrations of A and NA as determined by assay.Three developmental phases could be distinguished. In the first phase, the 16th and 17th prenatal day, medullary cells were only immunoreactive to DBH and NA, and only very small amounts of A as compared to NA were found. During the second period, from the 18th prenatal day to 2 or 3 days after birth, all medullary cells were immunoreactive to DBH, NA, PNMT and A, and during this phase the adrenaline concentration increased daily and became the predominant amine on the 20th day of gestation. Adrenaline represented 75% of total catecholamine on the 1st to 3rd day after birth. The third phase started at the 2nd or 3rd postnatal day and was characterized by the presence of an increasing number of medullary cells solely immunoreactive to DBH and NA, hence synthesizing and storing NA. The remaining cells were immunoreactive to DBH, NA, PNMT and A. Postnatally, the relative concentration of A continued to rise reaching 79% by the 4th postnatal day. These results indicate that initially the adrenal medullary cells are synthesizing and storing almost exclusively NA. Probably, adrenaline synthesis begins at the 16th–17th day of gestation and the cells are then capable of synthesizing and storing both NA and A (mixed cell type) with A synthesis and storage rapidly becoming predominant. Finally, after birth, separate NA-synthesizing and -storing cell types are formed and the so-called A cells stored predominantly (probably >90%) adrenaline with a small proportion of noradrenaline.In the medullary blastema and in the sympathetic ganglia of prenatal animals two cell types, only immunoreactive to DBH and NA, were observed. Presumably, these cells represent developing sympathetic neurons and extra-adrenal chromaffin cells; the latter cell type occasionally invades the adrenal gland. Thus, prospective medullary cells are able to synthesize and store NA before they have made contact with the cortical blastema but A-synthesizing cells are found only within the adrenal gland.Low but significant amounts of DA were found in the adrenal before birth and during the first two postnatal weeks but in the adult animal this accounted for less than 0.1% of total catecholamine.Preliminary reports of this study were made to the American Association of Anatomists (Anat. Rec. 196; 196A, 1980), the Dutch Anatomical Society (Acta Morphol. Neerl. Scand. 19; 330, 1981, and the XIIIth Acta Endocrinologica Congress (Acta Endocrinol. 97: Suppl. 243, 285, 1981)     

Fate of intraocular chromaffin cell suspensions: role of initial nerve growth factor support

Summary Adrenal medullary tissue from adult rats was dissociated into cell suspensions and injected into the anterior chamber of the eye, where the cells were made to attach to the previously sympathectomized irides with the use of fibronectin. Short- and long-term survival of the chromaffin cells was examined in whole mounts of irides using Falck-Hillarp fluorescence histochemistry or indirect immunohistochemistry with antibodies against adrenaline and dopamine--hydroxylase (DBH). After 6 days in oculo all cells were immunoreactive for adrenaline; almost none displayed processes even if -nerve growth factor (NGF) was given at grafting. One month after weekly intraocular injections of NGF, many cells were surrounded by nerve fiber net-works and all cells were DBH-immunoreactive. Eight months postgrafting and 7 months after the last injection of NGF almost the entire iris was reinnervated and resembled a normal, sympathetically innervated iris. Both at 1 and 8 months, chromaffin cells, ganglion cells and transitional cell forms (chromaffin cells transforming towards ganglion-like cells) were found in irides from the NGF-treated eyes. The number of ganglion cells was remarkably increased with time by NGF, while the number of chromaffin cells decreased compared to controls. A single treatment with NGF at grafting had no marked effects as examined up to 3 months; at this time there was a certain outgrowth of nerve terminals, which, however, was not as pronounced as 1 month after repeated NGF injections. In conclusion, it is shown that some cells in a chromaffin cell suspension attach to the iris, transform to ganglion cells after an induction with exogenous NGF, and reinnervate the sympathically denervated iris. Such cells remain ganglion-like in character and continue to form processes even after cessation of exogenous NGF treatment.     

Development of the adrenal medullary cells in rats with reference to synaptogenesis

Summary The adrenal medullae of rats were studied electron microscopically from day 13.5 of gestation. Synapses with thickening of pre- and post-synaptic membranes were first evidenced on the medullary cells of 15.5-day-old fetuses. They increased gradually in number with advancing age. In the medullary cells, a few membrane-limited granules were recognized on day 13.5 of gestation, and thereafter they increased in number. The appearance of the granules was not uniform; some of the granular contents consisted of fine or coarse particles and others contained homogeneous material of varying electron-densities. The population of these granules in the cytoplasm was different from cell to cell. Thus, the discrimination of cell types (NA- and A-cells) was not possible in the prenatal period. Granular discharge of the cells was totally absent in the normal untreated fetuses. However, upon the intraperitoneal administration of insulin to the fetus on day 16.5, 18.5, or 21.5 of gestation, granular discharge by reverse pinocytosis was first evidenced in the medullary cells of the 21.5-dayold fetus.     

On the uptake of exogenous catecholamines by adrenal chromaffin cells and nerve endings

Summary Light-microscopic autoradiography has revealed characteristic labelling patterns in adrenal medullary cells following the intravenous administration of different catecholamines. The uptake patterns for [³H] dopa, [³H] dopamine, [³H] noradrenaline and [³H] adrenaline have been compared. In all cases A cells were more active than NA cells and cells situated in the zone nearest the cortex demonstrated a markedly higher rate of uptake than central cells. It was concluded that adjacent chromaffin cells with very similar morphology may differ as much as 50 fold in their capacities to incorporate exogenous amines. The adrenergic nature of the innervation of the vessels of the adrenal cortex and capsule in the mouse was confirmed.