ASSAY OF CORTICOTROPHIN PREDNISOLONE PRETREATMENT INSTEAD OF HYPOPHYSECTOMY IN THE ADRENAL ASCORBIC ACID DEPLETION TEST

1960 ◽  
Vol XXXV (IV) ◽  
pp. 594-603 ◽  
Author(s):  
Christian Hamburger
Keyword(s):  
Ascorbic Acid ◽  
Adult Male ◽  
Subcutaneous Injection ◽  
Aqueous Suspension ◽  
Inhibitory Effect ◽  
Male Rats ◽  
Synthetic Analogues ◽  
Single Subcutaneous Injection ◽  
Calibration Curves ◽  
Intact Rats

ABSTRACT The inhibitory effect of various corticosteroids and synthetic analogues on the stress-induced release of corticotrophin was measured in adult male rats by means of the adrenal ascorbic acid depletion test. All the compounds examined were active, dexamethasone and prednisolone being the most effective inhibitors. A single subcutaneous injection of a microcrystalline aqueous suspension of prednisolone (1.5 mg per rat), given about 2 hours before left-sided adrenalectomy, blocked completely the adrenal ascorbic acid depletion. Quantitative assays of a purified corticotrophin preparation were carried out with hypophysectomized and prednisolone-treated intact rats. The latter were less sensitive to corticotrophin, but the slopes of the calibration curves and the standard deviations appeared to be the same in both instances. It is concluded that it is feasible to replace the surgical hypophysectomy by prednisolone pretreatment in the ascorbic acid depletion test for corticotrophin.

Renal Cortical Slice Uptake and Runout of N-methylnicotinamide and p- Aminohippurate after Potassium Dichromate Treatment

1974 ◽  
Vol 52 (3) ◽  
pp. 465-468 ◽  
Author(s):  
G. H. Hirsch ◽  
A. P. Pakuts
Keyword(s):  
Adult Male ◽  
Subcutaneous Injection ◽  
Potassium Dichromate ◽  
Male Rats ◽  
Significant Enhancement ◽  
Cortical Slice ◽  
Single Subcutaneous Injection ◽  
Kidney Slices ◽  
Renal Cortical Slice ◽  
Cortical Slices

Administration of 40 mg/kg potassium dichromate to adult male rats produced a significant enhancement of N-methylnicotinamide (NMN) uptake by renal cortical slices when measured 24 h after a single subcutaneous injection. Incubation under nitrogen or in the presence of dinitrophenol reduced NMN accumulation by kidney slices from control and treated rats to the same level. The rate of NMN runout was slower in renal cortical slices from rats treated with 40 mg/kg potassium dichromate, while p-aminohippurate (PAH) runout was significantly greater than control.

Maintained Hypersexuality between Male Rats following Chronically Induced Limbic Seizures: Implications for Bisexuality in Complex Partial Epileptic Seizures

1994 ◽  
Vol 74 (2) ◽  
pp. 647-652 ◽  
Author(s):  
M. A. Persinger
Keyword(s):  
Adult Male ◽  
Subcutaneous Injection ◽  
Epileptic Seizures ◽  
Male Rats ◽  
Albino Rats ◽  
Limbic Seizures ◽  
Single Subcutaneous Injection

Adult male albino rats were given a treatment that produced hypothermia after the induction of limbic seizures by a single subcutaneous injection of lithium and pilocarpine. When housed in groups, these rats exhibited marked hypersexuality (for at least two months), defined as repeated mounting of another male, pelvic thrusting, and persistent genital licking; while the male was mounted, female postures were assumed. There were also periods of physical submission. During active periods three of the four rats were mounted and thrusting in tandem. Possible relevance to the Klüver-Bucy syndrome and to bisexuality and homosexuality in males who report elevated complex partial epileptic-like signs is discussed.

scholarly journals Dietary ascorbic acid lowers the concentration of soluble copper in the small intestinal lumen of rats

1994 ◽  
Vol 71 (5) ◽  
pp. 701-707 ◽  
Author(s):  
G. J. Van Den Berg ◽  
S. YU ◽  
A. G. Lemmens ◽  
A. C. Beynen
Keyword(s):  
Ascorbic Acid ◽  
Small Intestine ◽  
Liquid Phase ◽  
Inhibitory Effect ◽  
Male Rats ◽  
Intestinal Lumen ◽  
Distal Intestine ◽  
Small Intestinal ◽  
Ascorbic Acid Supplementation

We tested the hypothesis that ascorbic acid in the diet of rats lowers the concentration of soluble Cu in the small intestine, causing a decrease in apparent Cu absorption. Male rats were fed on diets adequate in Cu (5 mg Cu/kg) without or with 10 g ascorbic acid/kg. The diet with ascorbic acid was fed for either 6 or 42 d. Ascorbic acid depressed tissue Cu concentrations after a feeding period of 42, but not after 6 d. Dietary ascorbic acid lowered apparent Cu absorption after 6, but not after 42 d. The lowering of tissue Cu concentrations after long-term ascorbic acid feeding may have increased the efficiency of Cu absorption, and thus counteracted the inhibitory effect of ascorbic acid. Dietary ascorbic acid caused a significant decrease in the Cu concentrations in the liquid phase of both the proximal and distal parts of the small intestinal lumen. This effect was due to both a decrease in the amount of Cu in the liquid digesta and an increase in the volume of the liquid phase; only the latter effect for the distal intestine was statistically significant. We conclude that ascorbic acid supplementation lowers Cu absorption by decreasing the concentration of soluble Cu in the small intestine.

EFFECTS OF SERUM AND HYPOTHALAMIC EXTRACTS IN INTACT AND HYPOPHYSECTOMIZED RECIPIENTS OF THE PARLOW TEST

1967 ◽  
Vol 55 (4) ◽  
pp. 611-621 ◽  
Author(s):  
C. A. de Groot
Keyword(s):  
Ascorbic Acid ◽  
Pituitary Gland ◽  
Adult Male ◽  
Normal Serum ◽  
Boiling Water ◽  
Male Rats ◽  
Boiling Water Bath ◽  
Donor Material ◽  
Tissue Extracts ◽  
Hypothalamic Tissue

ABSTRACT Serum from intact and from hypophysectomized adult male rats induces an ovarian ascorbic acid depletion in intact immature pseudopregnant recipients. When the recipients are in addition hypophysectomized, only the effect obtained with hypophysectomized donor serum is found, while normal serum is inactive. Similar results are seen when, instead of serum, hypothalamic tissue extracts are injected. Normal serum and hypothalamic tissue apparently act by way of the recipients' pituitary gland, and hence, by LH-RF. The effect produced by hypophysectomized donor material in hypophysectomized recipients is probably non-specific. In parallel experiments it was found that not all depleting activity is lost by heating adenohypophyseal extracts for 15 minutes in a boiling water-bath.

Effects of Melatonin and Natural and Synthetic Analogues of Arginine Vasotocin on Plasma Prolactin Levels in Adult Male Rats

1978 ◽  
Vol 9 (4) ◽  
pp. 236-246 ◽  
Author(s):  
Mary K. Vaughan ◽  
John C. Little ◽  
Linda Y. Johnson ◽  
David E. Blask ◽  
George M. Vaughan ◽  
...  
Keyword(s):  
Adult Male ◽  
Arginine Vasotocin ◽  
Male Rats ◽  
Plasma Prolactin ◽  
Synthetic Analogues ◽  
Natural And Synthetic

Vitamin E Stimulates Luteinizing Hormone-Releasing Hormone and Ascorbic Acid Release from Medial Basal Hypothalami of Adult Male Rats

2003 ◽  
Vol 228 (7) ◽  
pp. 779-785 ◽  
Author(s):  
S. Karanth ◽  
W.H. Yu ◽  
C.A. Mastronardi ◽  
S.M. McCann
Keyword(s):  
Ascorbic Acid ◽  
Vitamin E ◽  
Luteinizing Hormone ◽  
Adult Male ◽  
Male Rats ◽  
Soluble Form ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Lhrh Release

Vitamin E, a dietary factor, is essential for reproduction in animals. It is an antioxidant present in all mammalian cells. Previously, we showed that ascorbic acid (AA) acted as an inhibitory neurotransmitter in the hypothalamus by scavenging nitric oxide (NO). Earlier studies have shown the antioxidant synergism between vitamin E and ascorbic acid (AA). Therefore, it was of interest to evaluate the effect of vitamin E on luteinizing hormone-releasing hormone (LHRH) and AA release. Medial basal hypothalami from adult male rats of the Sprague Dawley strain were incubated with Krebs-Ringer bicarbonate buffer or graded concentrations of a water soluble form of vitamin E, tocopheryl succinate polyethylene glycol 1000 (TPGS, 22–176 μM) for 1 hr. Subsequently, the tissues were incubated with vitamin E or combinations of vitamin. E + N-methyl-D-aspartic acid (NMDA), an excitatory amino acid for 30 min to study the effect of prior and continued exposure to vitamin E on NMDA-induced LHRH release. AA and LHRH released into the incubation media were determined by high-performance liquid chromatography and radioimmunoassay, respectively. Vitamin E stimulated both LHRH and AA release. The minimal effective concentrations were 22 and 88 μM, respectively. NMDA stimulated LHRH release as previously shown and this effect was not altered in the combined presence of vitamin E plus NMDA. However, AA release was significantly reduced in the combined presence of vitamin E plus NMDA. To evaluate the role of NO in vitamin E-induced LHRH and AA release, the tissues were incubated with vitamin E or combinations of vitamin E + NG-monomethyl-L-arginine (NMMA), a competitive inhibitor of NO synthase. NMMA significantly suppressed vitamin E-induced LHRH and AA release indicating a role of NO in the release of both LHRH and AA. The data suggest that vitamin E plays a role in the hypothalamic control of LHRH and AA release and that the release is mediated by NO.

Tamoxifen does not block the inhibitory effect of testosterone on FSH release in rats

1987 ◽  
Vol 114 (1) ◽  
pp. 84-89
Author(s):  
P. Negri-Cesi ◽  
F. Celotti ◽  
R. C. Melcangi ◽  
M. Zanisi ◽  
M. Motta
Keyword(s):  
Adult Male ◽  
Testosterone Propionate ◽  
Day Treatment ◽  
Elevated Serum ◽  
Serum Levels ◽  
Inhibitory Effect ◽  
Male Rats ◽  
Concomitant Treatment ◽  
Lh Release ◽  
Series Of Experiments

Abstract. The aim of the present experiments was to analyze whether the inhibitory effect exerted by testosterone on FSH release might be mediated by the intracerebral transformation of the hormone into oestrogenic metabolites. Advantage has been taken of the availability of the potent antioestrogen tamoxifen. Two series of experiments have been performed. In the first one, adult male rats have been castrated and submitted, beginning immediately after surgery, to a 6-day treatment with testosterone propionate (2 mg/rat/day), tamoxifen (50 or 200 μg/rat/day) or testosterone propionate (2 mg/rat/day) plus tamoxifen (either 50 or 200 μg/rat/day). In the second experiment, adult male rats have been castrated and submitted to the same 6-day treatments, beginning 4 weeks following orchidectomy. In both experiments, the animals were killed 24 h after the last injection, and serum levels of FSH and LH have been measured by radioimmunoassays. The results have clearly shown that, in both experiments, the administration of testosterone results in a significant decrease of serum FSH and in a total suppression of LH release. The administration of tamoxifen, in either dose, does not modify the elevated serum FSH and LH levels present in the orchidetomized animals, and does not antagonize the inhibitory effect on FSH and LH secretion exerted by the concomitant treatment with testosterone propionate. It is concluded that testosterone inhibits FSH secretion in orchidectomized rats acting as such, and not following aromatization to oestrogens.

scholarly journals The effect of intra-nucleus accumbens shell injection of ascorbic acid on spatial learning and memory in adult male rats

2015 ◽  
Vol 2 (1) ◽  
pp. 73-81
Author(s):  
Fateme Shahsavari ◽  
Mahdi Abbasnejhad ◽  
Reihane Naderi ◽  
Saeed Esmaeeli Mahani ◽  
◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Nucleus Accumbens ◽  
Learning And Memory ◽  
Spatial Learning ◽  
Adult Male ◽  
Male Rats ◽  
Spatial Learning And Memory ◽  
Nucleus Accumbens Shell

THE EFFECTS OF HYPOPHYSECTOMY AND TESTOSTERONE ON THE ACTIVITY OF THE SEBACEOUS GLANDS OF CASTRATED RATS

1970 ◽  
Vol 47 (2) ◽  
pp. 219-224 ◽  
Author(s):  
A. J. THODY ◽  
S. SHUSTER
Keyword(s):  
Adult Male ◽  
Testosterone Propionate ◽  
Male Rats ◽  
Preputial Gland ◽  
Sebaceous Glands ◽  
Gland Weight ◽  
Preputial Glands ◽  
Sebum Secretion ◽  
Intact Rats

SUMMARY Adult male rats which had been castrated prepuberally secreted less sebum than intact rats. When hypophysectomy followed castration there was a further decrease in sebum secretion. Treatment of the castrated and hypophysectomized castrated rats with testosterone propionate produced a large and comparable increase in the sebum secretion of both groups. Testosterone propionate also caused a marked increase in the preputial gland weight of the castrated rats, although a much smaller response occurred after hypophysectomy. The effect of hypophysectomy on the response of the sebaceous and preputial glands to testosterone is discussed.

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