Prolactin Suppression and Spermatogenic Developments in Maturing Rats. A Quantitative Study

Nag, Sumitra; Sanyal, Suparna; Ghosh, Kalyan; Biswas, N. M.

doi:10.1159/000179436

Cited by 18 publications

(10 citation statements)

References 3 publications

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“…Now if we analyse the effect of exogenous testosterone in presence of different concentrations of bromocriptine, it becomes clear that testosterone antagonistic action of bromocriptine depends upon the levels of blood PRL-tetres. Previously it has been reported from our laboratory that PRL antagonizes bromocriptine-induced mppression of ARC weight in maturing rats (Nag et al -1981).…”

Section: Discussionmentioning

confidence: 81%

Bromocriptine Induced Hypoprolactinemia and Accessory Reproductive Glands Response to Testosterone in Castrated Male Rats

2009

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Now-a-days it is well established that prolactin (PRL) affects the growth of male accessory-reproductive glands (ARC) (Bartke -1976). In castrated animals, PRL has been shown to potentiate the effect of exogenous androgens on male sex-accessories (Thomas and Keenan -1976; Boyns et al. -1972). However, administration of PRL alone to castrated rats yielded controversial results; a number of investigators reported small but detectable increase in the ARC (Bartke and Lloyd -1970; Negro-Vilar et al. -1977), while it has been argued by others (Harper et al. -1976). Since PRL is believed to be involved in the physio-Papadopoulos -1954).Radioimmunoassay for PRL was done with double antibody technique using materials and instructions supplied by NIAMDD, Maryland, U.S.A. All samples from the study were measured in the same assay at two dilutions in duplicate. Intraassay coefficient of variation

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Section: Discussionmentioning

confidence: 81%

Bromocriptine Induced Hypoprolactinemia and Accessory Reproductive Glands Response to Testosterone in Castrated Male Rats

2009

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“…Male patients with prolactinoma often show decreased libido, impotence, disturbance of T production, and disturbance of sperm production as reported by many authors (Abbassy & Saikali, 1982;Carter et al, 1978;Fraioli et al, 1980;Franks et al, 1978;Grisoli et al, 1980;Murray et al, 1984;Nag et al, 1981;Prescott et al, 1982;Sharpe & McNeilly, 1979). However, there has rarely been a study of hypothalamic dysfunction, particularly pulsatile secretion of LH, in male prolactinoma (Ambrosi et al, 1985).…”

Section: Discussionmentioning

confidence: 93%

Hypogonadism of male prolactinomas: Relation to pulsatile secretion of LH: Hypogonadisms des Mannes mit Prolaktinomen: Beziehungen zur pulsatilen LH-Sekretion

et al. 2009

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In order to investigate whether a hypothalamic disorder cause hypogonadism in male prolactinomas, LH pulsatile secretion was studied in 13 male patients. Serum PRL levels ranged from 186 to 45,000 ng ml-' before treatment, and all the tumors were macroadenomas. Reduced LH secrection was revealed in 5 of 13 patients, and FSH was reduced in 1 of 13. Serum testosterone (T) levels were lower than the normal limit in all the patients. HCG tests in 3 patients showed good responses, but the peak values of T were lower than those of normal men. LH pulsatilities were examined in 5 hyperprolactinemic patients before treatment, in 4 hyperprolactinemic patients after operation, and in 8 normoprolactinemic patients after operation and/or bromocriptine treatment. There was no significant difference of the mean LH values, the frequencies of LH pulses, and amplitudes among the hyperprolactinemic patients before operation (n = 5), the normoprolactinemic patients after operation (n = 8), and normal men (n = 7). From these results, it was evident that the hypothalamus and pituitary function of male prolactinomas were well preserved, in spite of higher serum PRL levels and larger tumor size than those reported in females. It is suggested that the main cause of hypogonadism in these patients is due to testicular dysfunction resulting from excessive serum PRL.Zusammenfassung. Um die Frage zu klaren, ob eine Storung des Hypothalamus den Hypogonadismus des Mannes bei Prolaktinom verursacht, wurde die pulsatile LH-Sekretion bei 13 Mannern untersucht. Die Serum-Prolaktinwerte lagen zwischen 186 und 45.000 ng/ml vor der Behandlung; alle Tumoren waren Makroadenome. Bei 5 von 13 Patienten fand sich eine reduzierte LH-Sekretion. Serum-Testosteron lag niedriger als normal bei allen Fallen. HCG-Tests zeigten in 3 Fallen gute Reaktionen, aber die Spitzenwerte waren niedriger als bei normalen Mannern. Bei 5 Mannern wurden die LH-Pulsatile vor der Behandlung untersucht, viermal nach der Operation und in 8 Fallen mit normalen Prolaktinwerten nach Operation und/oder Bromokryptinbehandlung. Es ergab sich keine signifikante Differenz zwischen den Mittelwerten fur LH, den Frequenzen der LH-Pulse und den Amplituden unter den hyperprolaktinamischen Mannern vor der Operation (n= 5), dennormoprolaktinamischen Mannern nach der Operation (n= 8) und den normalen 520 Y. Saitoh et al. Mannern (n = 7). Aufgrund dieser Ergebnisse ist es nach Auffassung der Autoren bewiesen, daR die Hypothalamus-und die Hypophysenvorderlappenfunktion von Mannern mitProlaktinomen gut geschutzt ist, trotz der hoheren Serumprolaktinwerte und des groReren Tumors als bei den bisher mitgeteilten Befunden bei Frauen. Das 1aRt daran denken, daR die Hauptursache des Hypogonadismus bei diesen Patienten im Hinblick auf die Hodendysfunktion von den erhohten Prolaktinwerten herruhrt.

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“…The intact, full-length protein was localized in the nucleus of round spermatids, while the truncated protein was localized in the Golgi apparatus of round spermatids and in the cytoplasm of elongated spermatids spermatozoa tails. These prolactin moieties may therefore account for the actions of prolactin in testicular function and spermatogenic development [39,40].…”

Section: Prolactinmentioning

confidence: 99%

Extrapituitary production of anterior pituitary hormones: an overview

2011

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Prolactin Suppression and Spermatogenic Developments in Maturing Rats. A Quantitative Study

Cited by 18 publications

References 3 publications

Bromocriptine Induced Hypoprolactinemia and Accessory Reproductive Glands Response to Testosterone in Castrated Male Rats

Bromocriptine Induced Hypoprolactinemia and Accessory Reproductive Glands Response to Testosterone in Castrated Male Rats

Hypogonadism of male prolactinomas: Relation to pulsatile secretion of LH: Hypogonadisms des Mannes mit Prolaktinomen: Beziehungen zur pulsatilen LH-Sekretion

Extrapituitary production of anterior pituitary hormones: an overview

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