EFFECT OF HYPOTHALAMIC LESIONS ON PITUITARY MELANOCYTE-STIMULATING HORMONE

1967 ◽  
Vol 39 (4) ◽  
pp. 485-NP ◽  
Author(s):  
S. TALEISNIK ◽  
J. DE OLMOS ◽  
R. ORÍAS ◽  
MARÍA E. TOMATIS
Keyword(s):  
Median Eminence ◽  
Male Rats ◽  
Posterior Lobe ◽  
Melanocyte Stimulating Hormone ◽  
Mammillary Bodies ◽  
Hypothalamic Lesions ◽  
Paraventricular Nuclei ◽  
Inhibiting Factor ◽  
Electrolytic Lesions ◽  
Stimulating Hormone

SUMMARY The effect on the content of melanocyte-stimulating hormone (MSH) activity in the pituitary of electrolytic lesions placed in different regions of the hypothalamus was studied in male rats. Lesions in the paraventricular nuclei resulted, after 15 days, in a decrease of pituitary MSH activity to 20·4 ± 4·5%/mg. gland as compared with the controls, without changes in the weight of the hypophyses. In a group of animals in which the lesions failed to destroy the paraventricular nuclei completely the MSH activity in the pituitary was 66·4 ± 7·5% of that of controls and the weight of the gland was significantly higher. Hypothalamic lesions in the median eminence of the tuber cinereum produced 24 hr. later a decrease of pituitary MSH activity to 6·6 ± 0·8%, but 15 days later the values/mg. gland were almost normal. Lesions placed in the mammillary bodies or in the nucleus caudatus did not affect pituitary MSH content. Extracts of stalk-median eminence or posterior lobe from animals with lesions in the paraventricular nuclei, failed to show MSH-releasing factor as it is found in intact animals, nor did they contain MSH-release-inhibiting factor. The results support the concept that the paraventricular nuclei are involved in the control of pituitary MSH secretion and suggest that the MSH content of the disconnected hypophysis is to some degree regulated autonomously.

INFLUENCE OF RESERPINE ON THE PITUITARY CONTENT OF MELANOCYTE-STIMULATING HORMONE AND ON HYPOTHALAMIC FACTORS WHICH AFFECT ITS RELEASE

1968 ◽  
Vol 42 (4) ◽  
pp. 505-512 ◽  
Author(s):  
MARIA E. TOMATIS ◽  
S. TALEISNIK
Keyword(s):  
Median Eminence ◽  
Normal Values ◽  
Male Rats ◽  
Normal Male ◽  
Melanocyte Stimulating Hormone ◽  
Inhibiting Factor ◽  
Pituitary Glands ◽  
Stimulating Hormone

SUMMARY The melanocyte-stimulating hormone (MSH) content of whole toad pituitary glands decreased upon treatment with reserpine. With daily injections the values remained low for 1 week but regained normal levels after 2 weeks in spite of an increased secretion of MSH as indicated by darkening of the skin. In rats a drop in pituitary MSH content also occurred after reserpine injection but normal values were found after 7 and 14 days of treatment. MSH-releasing factor found in stalk-median eminence tissue of normal male rats was not present in the reserpine-injected animals, but after 7 days of treatment an increase in MSH-release-inhibiting factor (MSH-R-IF) was demonstrated. MSH-R-IF was also found to have increased in female castrated rats after 2 days of treatment with reserpine. It is concluded that reserpine permits the secretion of pituitary MSH by blocking the release of MSH-R-IF, which accumulates in the hypothalamic neurones.

A melanocyte-stimulating hormone-releasing factor in hypothalamic extracts

1965 ◽  
Vol 208 (2) ◽  
pp. 293-296 ◽  
Author(s):  
S. Taleisnik ◽  
R. Orías
Keyword(s):  
Nervous System ◽  
Cerebral Cortex ◽  
Intravenous Injection ◽  
Median Eminence ◽  
Melanocyte Stimulating Hormone ◽  
Hypothalamic Lesions ◽  
Stimulating Hormone

Intravenous injection of rat stalk median eminence (SME) extracts to rats produced a decrease in the pituitary melanocyte-stimulating hormone (MSH) activity. This effect was not obtained with injection of cerebral cortex extract, nor with histamine, norepinephrine, vasopressin, or oxytocin. A slight decrease occurred with epinephrine. The response to 2, 1, 1/2, 1/4, and 1/8 of SME was linearly related to the logarithm of the doses. It is inferred that hypothalamic extracts evoked a decrease in MSH pituitary content, since doses of 1/4 SME, which lowered the pituitary MSH activity more than 50%, did not modify the concentration in ACTH. No changes in MSH pituitary activity were obtained in animals submitted to stress. It is concluded that SME extracts contain a MSH-releasing factor which acts directly on the hypophysis and not through the nervous system, since it is effective in rats with hypothalamic lesions in the median eminence area.

THE EFFECT OF HYPOTHALAMIC LESIONS ON REPRODUCTIVE ACTIVITY IN SHEEP

1967 ◽  
Vol 39 (3) ◽  
pp. 415-NP ◽  
Author(s):  
H. M. RADFORD
Keyword(s):  
Median Eminence ◽  
Reproductive Activity ◽  
Mammillary Body ◽  
Optic Chiasma ◽  
Hypothalamic Lesions ◽  
Apparent Change ◽  
Electrolytic Lesions ◽  
Releasing Factors ◽  
Bilateral Lesions ◽  
Made In

SUMMARY Electrolytic lesions were made in the hypothalamus of 41 Merino ewes which were subsequently observed for 2–16 months. Ovarian inactivity resulted from bilateral medial and ventral lesions placed immediately posterior to the optic chiasma (four ewes) or immediately anterior to the mammillary body (five ewes). Failure to show oestrus while apparently still ovulating regularly was a feature in another four ewes in which bilateral medial and ventral lesions were placed between the sites already described. Small bilateral lesions in these ventral regions led initially to ovarian inactivity, but final re-establishment of apparently normal reproductive activity in three ewes. Bilateral lesions in regions other than those described above resulted in no apparent change in reproductive activity (eight ewes). Similarly, unilateral or asymmetrical lesions in the remaining 17 ewes failed to affect their reproductive activity. The results are consistent with the hypothesis that in sheep a region of the median eminence responsible for the production of gonadotrophin-releasing factors requires neural inputs traversing both anterior and posterior hypothalamic areas.

Specific alterations in sodium chloride intake after hypothalamic lesions in the rat

1963 ◽  
Vol 205 (5) ◽  
pp. 922-926 ◽  
Author(s):  
Miguel R. Covian ◽  
José Antunes-Rodrigues
Keyword(s):  
Sodium Chloride ◽  
Urinary Excretion ◽  
The Other ◽  
Urinary Output ◽  
Water Ingestion ◽  
Hypothalamic Lesions ◽  
Paraventricular Nuclei ◽  
Electrolytic Lesions ◽  
Specific Increase ◽  
Sodium Chloride Intake

Bilateral electrolytic lesions in the hypothalamus of the rat elicited either a decrease or increase in 2% NaCl intake, without a significant change in water ingestion. Lesions placed in the anterior hypothalamus involving supraoptic or paraventricular nuclei, or both, resulted in a conspicuous fall (as much as 93%) of NaCl intake. The decreased consumption remained to the end of the experiments which in some rats lasted 105 days and was accompanied by a decrease in NaCl urinary output. On the contrary, lesions placed in the central hypothalamus determined a specific increase of NaCl intake together with an augmented urinary excretion. The increased ingestion was permanent and lasted to the end of the experiment, attaining in one rat the value of 290%. To account for these results two provisional explanations are advanced, one of them considering the possibility of the existence of two areas of opposite effects regarding NaCl ingestion and the other claiming a neurohumoral mechanism in which oxytocin and aldosterone could be the two responsible hormones.

scholarly journals Localization of Neuroendocrine Functions Within the Hypothalamus

1974 ◽  
Vol 1 (1) ◽  
pp. 29-39 ◽  
Author(s):  
Lee L. Bernardis
Keyword(s):  
Luteinizing Hormone ◽  
Preoptic Area ◽  
Follicle Stimulating Hormone ◽  
Hypothalamic Area ◽  
Paraventricular Nuclei ◽  
Inhibiting Factor ◽  
Hypothalamic Nuclei ◽  
Cyclic Control ◽  
Neuroendocrine Functions ◽  
Stimulating Hormone

SUMMARYThe results of lesion, stimulation, deafferentation, implantatión and transplantation studies employed in the identification of hypophysiotrophic control areas in the hypothalamus to date suggest the following probable locations: corticotropic releasing factor (CRF) is formed in a diffuse area along the base of the median eminence, if not the base of the entire hypothalamus. Follicle stimulating hormone releasing factor (FSHRF) is elaborated in the paraventricular-suprachiasmatic areas but its cyclic control may reside in the anterior hypothalamic area. Luteinizing hormone (LH) is controlled by luteinizing hormone releasing factor (LHRF) formed in the suprachiasmatic area: its cyclic control may be in the preoptic area. Prolactin is controlled by prolactin inhibiting factor (PIF) localized in a diffuse area comprising the ventromedial, dorsomedial, arcuate and paraventricular nuclei. The hypothalamic area involved in thyroid control is also rather large, since thyrotropin stimulating hormone releasing factor (TSHRF) has been found in an area including the supraoptic and chiasmatic nuclei. Growth hormone releasing factor (GHRF) is elaborated in a rather narrow zone, the ventromedial hypothalamic nuclei.

Effects of α-Melanocyte-Stimulating Hormone on Magnocellular Oxytocin Neurones and their Activation at Intromission in Male Rats

2006 ◽  
Vol 18 (9) ◽  
pp. 685-691 ◽  
Author(s):  
C. Caquineau ◽  
G. Leng ◽  
X. M. M. Guan ◽  
M. Jiang ◽  
L. Van der Ploeg ◽  
...  
Keyword(s):  
Male Rats ◽  
Melanocyte Stimulating Hormone ◽  
Oxytocin Neurones ◽  
Stimulating Hormone

Synthesis of analogues of the melanocyte-stimulating hormone release-inhibiting factor containing 2-oxoimidazolidine-1-carboxylic acid

1980 ◽  
Vol 45 (1) ◽  
pp. 294-297 ◽  
Author(s):  
Evžen Kasafírek ◽  
Ivan Krejčí ◽  
Vladimír Felt
Keyword(s):  
Amino Acid ◽  
Carboxylic Acid ◽  
Amino Acid Esters ◽  
Hormone Release ◽  
Melanocyte Stimulating Hormone ◽  
Inhibiting Factor ◽  
Carbonyl Chloride ◽  
Acid Esters ◽  
Stimulating Hormone

2-Oxoimidazolidine-1-carbonyl-leucyl-glycine amide (I), 2-oxoimidazolidine-1-carbonyl-leucyl-β-alanine amide (II), and 2-oxoimidazolidine-1-carbonyl-leucine amide (III) were synthesized by the acylation of corresponding dipeptide or amino-acid esters with 2-oxoamidazolidine-1-carbonyl chloride and following ammonolysis. Analogues I and II, containing 2-oxoimidazolidine-1-carboxylic acid instead of proline, exhibited the antiamnestic activity in the doses of 1 mg per kg subcutaneously, III was without effect.

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