Histochemical studies on the regeneration of aminergic nerves in rat cerebral artery after superior cervical ganglionectomy

The course of regeneration of aminergic nerves in rat cerebral arteries was studied by means of histochemical methods, after uni- or bilateral cervical sympathectomy. Degeneration of aminergic nerves started on day 1 and was complete between days 3 and 7 after surgery. Between weeks 4 and 6, regenerating nerves started to appear from the proximal internal carotid artery. Regenerated aminergic nerve fibres were generally unbeaded and intensity of fluorescence was weak. The circular nerves appeared earlier than the longitudinal ones. The number of regenerating nerves reached the maximum, between months 9 and 12, at about half the normal level. AChE activity of the cerebral arteries showed no significant changes at any stage.     

Effect of pinealectomy and of bilateral cervical ganglionectomy on serum LH levels in constant estrous-anovulatory rats.

The effects of pinealectomy or bilateral superior cervical ganglionectomy on serum luteinizing hormone (LH) levels and ovulation were studied in constant estrous-anovulatory rats bearing a frontal hypothalamic deafferentation (FHD). Ovulation returned in 65% of the animals undergoing pinealectomy or bilateral superior cervical ganglionectomy. Almost 50% of these ovulating animals showed elevated serum levels of LH on the day of vaginal proestrus, while the remainder ovulated without appreciable changes in serum LH concentrations. It is suggested that the absence of an LH peak in the latter cases was due to an insufficient sampling size. The results suggest that pinealectomy and cervical sympathectomy may result in LH release by interference with the hypothalamic and brain stem serotonergic system involved in the inhibition of LH release.     

Pinealectomy or superior cervical ganglionectomy do not alter reproduction in the wolf (Canis lupus)

Twelve wolves (6 male and 6 female) were used to study the role of the pineal in photoperiodic mediation of seasonal reproduction. Eight wolves were pinealectomized (PNX) or sham-pinealectomized (S-PNX) at 5 mo of age, and 4 were superior cervical ganglionectomized (SCGX) at 16 mo of age (2 males and 2 females per treatment). All attained puberty at the species-typical time, during their second breeding season, except 2 SCGX males that did not survive. Reproductive cycles of an additional male that was SCGX as an adult and the PNX and S-PNX wolves, followed for a minimum of 3 yr, did not differ from each other or from those of unoperated colony wolves on measures of serum testosterone and luteinizing hormone for males, or of serum estradiol and progesterone for females. Nor was the range of dates for ovulation different for treated vs. untreated females. Surgical transection of the olfactory tracts of 1 male and 1 female PNX wolf, inducing anosmia to control for the possibility of pheromonally synchronized cycles, also failed to alter the seasonality of these reproductive parameters. These results do not conform to the model of pineal mediation of sexual cycles for photoperiod-sensitive species. In spite of evidence for photoperiod influence, the wolf apparently relies on a system other than the pineal for seasonal control of reproduction.     

Effect of superior cervical ganglionectomy on monoamine content in the epithalamic area of the Mongolian gerbil (Meriones unguiculatus): A fluorescence histochemical study

Summary Extirpation of the superior cervical ganglion was performed in a series of Mongolian gerbils. One or two weeks after the ganglionectomy the animals were injected with a monoamine oxidase inhibitor. Subsequently perfusion fixation was performed using the glyoxylic acid-paraformal-dehydemagnesium method (Lorén et al., 1976) for fluorescence histochemical investigation of the monoamines of the pineal complex. In the ganglionectomized animals all of the blue-fluorescent sympathetic fibers in the pineal complex (superficial pineal gland, deep pineal gland and the pineal stalk) completely disappeared. The yellow indolamine fluorescence of the cells in the superficial pineal and the deep pineal, as well as in the pineal stalk, was markedly reduced after ganglionectomy. No change in the morphology or number of sympathetic fibers in the medial habenular nucleus was observed. These results indicate that the presence of sympathetic nerve fibers with perikarya in the superior cervical ganglion is necessary for maintaining a high indolamine content in all three parts of the pineal complex. In addition, the results also indicate that the deep pineal gland is a functional part of the pineal complex. The presence of a functionally active deep pineal, bordering the pineal recess, suggests that part of the pineal hormones might be secreted into the cerebrospinal fluid.This work was supported by the Carlsberg Foundation, the Swedish Natural Science Research Council, grant no. 2126-100, and the Danish Medical Research Council, grant no. 512-7134     

Antifertility effect of Andrographis paniculata (Nees) in male albino rat

Dry leaf powder of A. paniculata, when fed orally to male albino rats, at a dose level of 20 mg powder per day for 60 days, resulted in cessation of spermatogenesis, degenerative changes in the seminiferous tubules, regression of Leydig cells and regressive and/or degenerative changes in the epididymis, seminal vesicle, ventral prostate and coagulating gland. There was reduction in the weight and fluid content of the accessory glands. The treatment also resulted in accumulation of glycogen and cholesterol in the testis, and increased activities of lactate dehydrogenase in testis and alkaline phosphatase in testis and ventral prostate. The results suggest antispermatogenic and/or antiandrogenic effect of the plant.     

The role of adrenoreceptors in the regulation of oxytocin and vasopressin release after superior cervical ganglionectomy.

In male rats under anaesthesia, dialysis of the venous blood from sella turcica region was carried out. Vasopressin and oxytocin content was determined in the dialysates by radioimmunoassay. The obtained results indicate that: 1. Electrical stimulation of the superior cervical ganglion causes an increase in vasopressin and oxytocin release. 2. 20 days after superior cervical ganglionectomy the vasopressin and oxytocin release increased. 3. Superior cervical ganglionectomy immediately before the dialysis evoked a several times increase in vasopressin and oxytocin release. 4. Application of alpha1-blocker, prazosin, as well beta-blocker, propranolol, has partially prevented the increase in vasopressin release which was found immediately after superior cervical ganglionectomy. 5. Contrary to vasopressin, the increase in oxytocin release after superior cervical ganglionectomy is completely prevented by the beta-blocker, propranolol, and only partially by the alpha1-blocker, prazosin.     

Fine structural changes in the hamster pineal gland after blinding and superior cervical ganglionectomy

Pineal glands of male hamsters 8 weeks after removal of both eyes or both superior cervical ganglia and those of untreated animals were studied by electron microscopy. In the blinded hamsters the reproductive organs were remarkably involuted, whereas the pinealocytes enlarged and were characterized by a tremendous hypertrophy of the smooth-surfaced endoplasmic reticulum, in the mesh of which some dense cored vesicles were distributed. In constrast the pinealocytes of ganglionectomized hamsters atrophied and were noted by a large number of lysosomes and sparsity of the agranular reticulum, the testes being significantly larger than the controls. The findings were interpreted to be compatible with the view that the pineal capability of producing antigonadal substance is augmented by blinding and is suppressed by cervical ganglionectomy due to the impairment of normal functioning of the pineal by denervation. It is assumed that the degree of development of the smooth endoplasmic reticulum in the pinealocyte is parallel to, and reflects that of the pineal activity. Probably the membranous organelle is involved in the elaboration of the pineal antigonadal substance.     

Relationships between energy reserves and function in rat superior cervical ganglion

—Major components of the energy reserves of the isolated superior cervical ganglion (ATP, phosphocreatine, glucose, glycogen and lactate) were measured under aerobic and anaerobic conditions. Complete anaerobiosis was maintained by incubation in mineral oil through which N₂ had been bubbled. From the initial rate of change in the energy reserves, a metabolic rate was calculated which would be equivalent to the consumption of 93 m-moles of O₂ per kg per hour. Under aerobic conditions (oxygenated moist chamber) a similar metabolic rate was calculated. In contrast to the anaerobic state, initial energy expenditure was almost exclusively at the expense of glucose. Continuous supramaximal stimulation in O₂ increased energy expenditure by a factor of three; both glucose and glycogen were utilized from the outset, and lactate accumulated in the initial periods. Ganglionic transmission failed in both resting and stimulated states in spite of the continued presence of very substantial levels of ATP and phosphocreatine. Failure seemed to be associated not with ATP depletion but rather with the complete disappearance of glucose and glycogen.