Osmoregulation in nestling California gulls at Mono Lake,California

• 1.1. Hematocrit (Hct), plasma sodium ([Na]_pl), chloride ([Cl]_pl) and osmotic concentration (Osm_pl); volume and concentration of 1.0MNaCl induced salt gland secretion (SGS); and weights of osmoregulatory organs: kidneys, adrenal glands, and salt glands and nonosmoregulatory organs (liver and heart) were determined in nestling California gulls, Larus californiens (CG), on Krakatoa Islet, Mono Lake, California.
• 2.2. The mean Hct was 40.0% + 1.0%, the mean [Na]_pl and [Cl]_pl were 153.9 ± 0.9 and 110.1 ± 0.5 mM (n = 22); and the mean Osm_pl was 323.6 ± 1.3 mOsm/kg (n = 18).
• 3.3. In CG nestlings with a mean age of 10 days (n = 7), the mean SGS [Na] was 719 ± 19 mM and the birds secreted 81 ± 18% of the injected fluid containing 59 ± 13% of the injected Na. By the mean age of 23 days (n = 7), mean SGS [Na] was slightly higher (790 ± 30 mM than in younger birds (P < 0.05), but the percentage of secreted fluid (54 ± 10%) and Na (42 ± 6%) tended to be less.
• 4.4. In 18 CG nestlings mean organ weights (% body weight) were: kidneys 1.52 ±0.06%; salt glands, 0.13 ±0.01%, and adrenal glands 0.07 ±0.01%.
• 5.5. Nestling CG had significantly greater Hct (P < 0.001), [Na]_pl and [ci]_pl (P < 0.001), Osm_pl, (P < 0.005), and adrenal gland weight (P < 0.01), compared to nestling glaucous-winged Gulls (GWG), L. glaucescens (Hughes, 1984), which nest under cooler, moister conditions. CG kidney weight was smaller (P < 0.001); salt gland weight and salt excretion were the same as GWG.

     

The effect of ovine prolactin on sodium and water transport across the intestine of the fowl (Gallus domesticus)

• 1.1. The effects of ovine prolactin on sodium and water transport across the intestine of 9-day old cockerels were studied by an in vitro everted gut sac technique and by an in vivo balance technique.
• 2.2. Prolactin was found to reduce sodium and water transport across the jejunum and the rectum. AVP was ineffective.
• 3.3. Plasma sodium levels tended to decrease in prolactin treated birds.
• 4.4. It is suggested that the action of prolactin on intestinal salt and water transport is important in maintaining electrolyte homeostasis.

     

Hypocalcemic factor in the ultimobranchial gland of the frog,Rana rugosa

• 1.1. The hypocalcemic activity of the ultimobranchial gland of the frog, Rana rugosa, was estimated using a rat bioassay method.
• 2.2. Extracts of the ultimobranchial gland showed a very high hypocalcmic activity. The value corresponded to 6,340 mU (MRC)/kg b.w.
• 3.3. Serum inorganic phosphorus values of rats received the extract decreased in proportion to the dose, although no changes were found in serum sodium concentration.

     

Water diffusion,ion transport and lipid composition of the skin of Rana cyanophlyctis Schneider under osmotic stress

• 1.1. Analysis of the total lipid content (TL), components of the neutral lipid fraction (NLF), phospholipid fraction (PLF), recordings of electrical potential differences and diffusional permeability were carried out in the skin of the aquatic frog Rana cyanophlyctis subjected to in vivo salt stress (0.9 sodium chloride) for different durations (0, 1, 3 and 7 days).
• 2.2. A general decrease of skin TL and of components of the NEE and PEE was observed.
• 3.3. Stoichiometric ratios for skin PLF components under initial salt stress of different durations reveal an increase of the ratios of sphingomyelin and phosphatidyl choline after osmotic stress.
• 4.4. The diffusional permeability of water increased following exposure to salt stress of I, 3 and 7 days duration.
• 5.5. The transepithelial potential difference measured in vitro after a salt stress of 3 days was considerably higher than the controls.

     

The haemocytes and the activities of leucine aminopeptidase and alkaline phosphatase during development of Ceratitis capitata: Specific secretion of a leucine aminopeptidase isozyme

• 1.1. The types of haemocytes during larval development were studied.
• 2.2. The developmental profile of leucine aminopeptidase and alkaline phosphatase was studied. The maximum LAP activity was found to be in early larval development, while the maximum alkaline phosphatase during the white pupal stage.
• 3.3. These activities were compared with those determined in cell-free haemolymph.
• 4.4. Both hydrolytic enzymes have been found histochemically in the prohaemocytes and in the plasmatocytes.
• 5.5. In cultured haemocytes experiments it was found that 64% of the total LAP activity was secreted into the incubation medium, while electrophoretic analysis of released LAP activity demonstrated that only LAP A isozyme was secreted.
• 6.6. Based on the above results we suggest that both hydrolytic enzymes are functionally important throughout larval development.

     

Renal function in migrating adult atlantic salmon,Salmo salar L.

• 1.1. Renal function in migrating adult Atlantic salmon was studied in sea-water (SW) and following abrupt transfer to fresh water (FW).
• 2.2. Urine flow rate of SW-adapted fish, 0.72 ml/kg/hr, increased 6.3-fold to 4.55 ml/kg/hr after 2–3 days in FW, later decreasing to around 1 ml/kg/hr.
• 3.3. Changes in glomerular filtration rate and ion filtration rates largely paralleled changes in urine flow. In SW-adapted salmon about 4% of excreted magnesium is filtered. Tubular magnesium secretion declined within 1 day of FW transfer.
• 4.4. During the period of maximum diuresis, urinary sodium loss is 77% of the branchial sodium uptake rate. This falls to less than 20% in FW-adapted fish.

     

Serological and histochemical studies on the Achatina fulica galactan

• 1.1. Glycoconjugates in the albumin glands of Achatina fulica have been fractionated by combination of organic solvents, salt precipitation and chromatography on specific agarose-lectin beads.
• 2.2. A galactan consisting only of galactosyl residues was isolated from an agarose peanut-lectin matrix. It gave single precipitin arcs with many heterophile lectins in agar-gel electrophoresis.
• 3.3. The galactan exhibited selective serological reactivity with some galactose-specific lectins, (PNA, RCA, Tridacnins).
• 4.4. Histochemical studies with fluorescein-labelled lectins demonstrated the topochemical distribution of this galactan within the snail's albumin gland.

     

On the mechanism of decreasing the lithogenicity of bile in Camelus dromedarius

• 1.1. Analysis of camel bile revealed that it is highly concentrated.
• 2.2. The molar fraction of phospholipids in camel bile was low and cholesterol was very high relative to rat bile.
• 3.3. Cholate is the main primary bile acid secreted. Moderate quantities of the secondary bile acid deoxycholate were found but no lithocholate was detectable possibly secondary to rapid recycling of the bile acid pool in the enterohepatic circulation.
• 4.4. Glycoconjugated bile acids predominated over tauroconjugates.
• 5.5. The hepatic bile from the camel may be concentrated as part of the general mechanism of water conservation exhibited by that species. The increased concentration of bile acids helps maintain cholesterol in solution, thus reducing lithogenicity.

     

The influence of optic nerve section on blood metabolite levels in Carcinus maenas (Crustacea: Brachyura)

• 1.1. Blood metabolite levels were assayed in Carcinus maenas as an indicator of the functioning of the hyperglycemic hormone, HGH, secreted by the crab's eyestalk neuroendocrine tissue.
• 2.2. Bilateral eyestalk ablation eventually resulted in a hypoglycemic response after 2–3 days.
• 3.3. Bilateral optic nerve section produced a significant, long-term hypoglycemic response suggesting that release of HGH from the eyestalk sinus gland is controlled, via a promotive neural pathway, by the CNS and probably by the cerebral ganglia.
• 4.4. Injection of eyestalk extract into operated crabs consistently produced significant, short-term hyperglycemia.

     

Mammary extraction of plasma triglycerides in the cow during lactogenesis

• 1.1. In control cows, extraction of triglycerides from the circulation by the mammary gland increased abruptly and markedly, and the concentration of triglycerides in arterial plasma fell, on the day of parturition.
• 2.2. In cows that had fluid regularly removed from the mammary glands before parturition, these changes occurred at varying times from more than 4 days before parturition in an animal that secreted triglyceride copiously to 24 hr before parturition in an animal that secreted little triglyceride pre-partum
• 3.3. In all animals, the time when triglyceride extraction increased was close to the time when K⁺ concentration in the mammary secretion became maximal.

     

Studies on sodium-potassium-activated adenosinetriphosphatase—XV the rectal gland of the elasmobranchs

• 1.1. The enzyme NaK activated adenosinetriphosphatase (NaK ATPase) was found in high activity in the rectal gland of nine elasmobranch species.
• 2.2. Species with a radial arrangement of tubules in the gland had higher activities per kg body weight than species with lobular division of the glandular parenchyma.
• 3.3. The properties of the NaK ATPase system suggest that it has a primary, rate-limiting role in the NaCl secretion by this gland.

     

Epidermal growth factor alters the electrolyte profile of lactating ewes Ovis aries

• 1.1. Lactating ewes were treated with mouse epidermal growth factor (EGF) at a dose rate of 0.5 mg/day for 4 days and its effects on the electrolyte profile were observed.
• 2.2. There was no effect of EGF on plasma concentrations of sodium or potassium, although urinary and total (in urine and milk) losses of both were reduced.
• 3.3. EGF-induced hypocalcaemia was associated with reduced milk calcium secretion and increased urinary calcium excretion whereas EGF-induced hypermagnesaemia was associated with reduced urinary and total magnesium losses.
• 4.4. Glomerular filtration rate was reduced during EGF infusion.
• 5.5. Chronic intravenous EGF infusion affects the electrolyte profile by altering electrolyte secretion by the mammary gland and renal electrolyte excretion.

     

Pulmonary hypertension and the smooth muscle of the pulmonary arterioles in chickens at high altitude

• 1.1. One-day-old male (m) and female (f) chickens from a population living at 3300m for several generations were raised at 3300 m (HA) and at sea level (SL).
• 2.2. The histology of the pulmonary arterioles was studied in the HA and SL chickens when they were 4 weeks old and the thickness of their muscular coat (MT) determined.
• 3.3. Pulmonary arterial pressure (Ppa), hematocrit (Hct) and the wet and dry weights of the total ventricle, left ventricle, septum and right ventricle (RV) were obtained when the HA and SL birds were 8 weeks old.
• 4.4. Results indicated that chickens have a thick muscular coat in their pulmonary arterioles. MT expressed as a fraction of arteriolar diameter (MT/AD) was 0.113 at SL. Exposure to HA increased this value in the m (0.137, P < 0.01) but not in the f (0.123, P > 0.05).
• 5.5. Ppa, RV and Hct were significantly higher at HA in both sexes. The degree of pulmonary hypertension and right ventricular hypertrophy observed was smaller than that found in earlier generations of these chickens studied several years ago. This probably indicates some degree of adaptation after generations of life at HA.

     

The effect of egg-shell calcification on the response of plasma calcium activity to parathyroid hormone and calcitonin in the domestic fowl (Gallus domesticus)

• 1.1. The effects of Parathyroid Hormone and Calcitonin on the concentrations of ionised calcium, total calcium and phosphorus in the plasma of laying hens with and without a calcifying egg in the oviduct, were studied.
• 2.2. Parathyroid Hormone led to an increase in the plasma calcium activity in both groups of hens, but in non-egg calcifying birds this was preceded by a transient reduction in activity.
• 3.3. Calcitonin reduced the plasma calcium activity in non-egg calcifying birds but not in egg calcifying birds.
• 4.4. The significance of these effects in relation to the availability of bone calcium for shell production is discussed.

     

Non-transferrin-bound-iron in serum and low-molecular-weight-iron in the liver of dietary iron-loaded rats

• 1.1. The feeding of 0.5% (3,5,5-trimethylhexanoyl)ferrocene (TMH-ferrocene) in rats resulted in a severe and progressive liver siderosis (total liver iron, 30 mg/g liver wet weight, after 30 weeks).
• 2.2. High concentrations of an iron-rich ferritin (up to 250 mg/l) were detected in serum of heavily iron-loaded rats forming a large fraction of non-transferrin-bound-iron (5000 μg/dl in maximum).
• 3.3. Ferritin and not haemosiderin was the major iron storage protein in the liver.
• 4.4. The total liver iron concentration (from 0.4 to > 30 mg Fe/g wet wt) but not the cytosolic low-molecular-weight-iron fraction (from 0.5 to 2.5 μM) was extremely increased during iron-loading.

     

Interrelationship between metabolism of tritiated water, 22sodium and dry matter intake by beef cattle consuming wheat straw and poultry litter in free choice

• 1.1. Metabolism of tritiated water and ²²sodium was studied in six beef cows under Mediterranean summer conditions in order to find whether the turnover of these tracers can be used to evaluate pasture intake.
• 2.2. The diet of the cows included ad libitum access to two components which were given separately in different troughs: one was poultry litter and the other was wheat straw, to simulate the dry pasture.
• 3.3. Voluntary daily dry matter intake (111 g/kg^0.75) was unexpectedly high considering the low digestibility of the feed.
• 4.4. The assumptions of constant ratios of water intake to water turnover and of dry matter intake to water intake were confirmed. Consequently, dry matter intake was determined accurately from water turnover measurements.
• 5.5. Sodium intake was practically equal to sodium turnover and most of the sodium secreted in feces was of endogenous origin.
• 6.6. Pasture intake can be predicted from sodium turnover once the concentration in feed and water consumed is known.

     

Dufour's gland lipid chemistry of three species of Centris bees (hymenoptera: apoidea,anthophoridae)

• 1.1. Lipids secreted by the Dufour's glands of Centris (Hemisiella) analis, C. (Acritocentris) and C. (Centris) flavifrons consist primarily of odd-carbon alkanes (C19-C29).
• 2.2. More detailed GC/MS analyses of C. analis reveal a complex array of aliphatic esters, including a homologous series of tetradecenyl esters.
• 3.3. Within the genus, the linear Dufour's gland varies widely in proportional dimensions, with the elongate gland of C. flavifrons being exceptional.

     

Do birds possess brown adipose tissue?

• 1.1. Fluorescence and electron microscopy were used to visualize differences between avian adipose tissue (AAT) collected from clavicular and abdominal regions of the great tit, the willow tit, the house sparrow and the Japanese quail, and interscapular brown adipose tissue (BAT) obtained from the Djungarian dwarf hamster.
• 2.2. Multilocular fat cells were found in AAT. The prerequisite for multilocularity, however, was not simply winter acclimatization [short photophase 4L:20D and low ambient temperature (< −20°C in January in Oulu)] or cold-acclimation (−25°C). Multilocular adipocytes were found during autumn and in unacclimated control birds as well. Mitochondria in the AAT were fewer and about one-sixth the length of those in BAT. This finding was associated with low cytochrome oxidase (COX) activity in the tissue homogenate and isolated mitochondrial fraction of the AAT (< 5.2% of that in BAT).
• 3.3. Catecholamine fluorescence was seen only around arteries in the AAT. Signs of sympathetic parenchymal innervation were found neither in winter- nor in cold-acclimated birds, but typically, sympathetic nerve fibers forming a basket-like network around every cell were seen in the brown fat of the hamster.
• 4.4. Our results show that AAT in the adult birds resembles white adipose tissue more than brown. Multilocularity of adipocytes may improve lipolysis to deliver fatty acids for muscle fuel of shivering or NST.

     

Some properties of the NADP-malic enzyme from mango fruit,Mangifera indica

• 1.1. Malic enzyme l-malate-NADP-oxidoreductase (oxaloacetate-decarboxylating) (EC 1.1.1.40) was located in the cytosolic fraction of ripening mango fruit.
• 2.2. The purified enzyme has an isoelectric point of 6.86 and an activation energy of 11.9kcal/mol.
• 3.3. The amino acid composition of the enzyme was determined and revealed a low cysteine and tryptophan content.
• 4.4. The enzyme has an ultraviolet absorption maximum at 266 nm with maxima for fluorescence excitation and emission at 285 and 328 nm.
• 5.5. The enzyme shows positive cooperativity between the malate binding sites and the effect of allosteric regulators and structural analogues on the activity were investigated.

     

The effect of eyestalk ablation on growth,haemolymph composition and gill Na+, K+-ATPase activity of Penaeus monodon juveniles

• 1.1. Eyestalk unablated and unilaterally ablated Penaeus monodon juveniles had survival rates after 5 months of 75–72.5 and 67.5–60%, respectively.
• 2.2. Unilaterally ablated shrimps had significantly higher (P < 0.05) growth rate than unablated shrimps.
• 3.3. Eyestalk-ablatement resulted in a decrease in the haemolymph sodium concentration and an increase in the potassium and calcium concentration of shrimps.
• 4.4. The osmolarity of haemolymph and total protein concentration of unablated shrimps were demonstrated to be higher than those of unilaterally ablated shrimps.
• 5.5. The eyestalk-ablated shrimps possess higher total ATPase and Na⁺,K⁺-ATPase activities in the gill than those of unablated shrimps.