Prolactin and Osmoregulation in Vertebrates

Abstract

Studies on the roles of prolactin in vertebrate osmoregulation have expanded in recent years to include examination of ionic and osmotic factors contributing to the regulation of secretion by paraneuronal prolactin-secreting cells and the effects of prolactin on a number of ion- and water-transporting epithelial tissues. Coupled with information on whole-animal homeostatic effects, the application of surgical, tissue-culture, biophysical and biochemical techniques to individual components will facilitate broader and more integrated functional analyses of the important osmoregulatory effects of this hormone in all vertebrate classes.

Plasma prolactin and cortisol concentrations of stressed coho salmon, Oncorhynchus kisutch, in fresh water or salt water

“…3C) and hydromineral disturbance reported by others (Lahlou and Giordan, 1970;Pit et al, 1974;Mazeaud et al, 1977;Pit, 1978;Eddy and Bath, 1979;Eddy, i981). Prolactin is known to help fish maintain homeostasis in FW (Hirano and Mayer-Gostan, 1978;Loretz and Bern, 1982;Hirano, 1986), and lowered plasma osmotic pressure has often been related to increased plasma prolactin level (Prunet et al, 1985;Avella et al, 1990). The potential involvement of prolactin in response to stress in SW is difficult to explain.…”

“…Prolactin is believed to act as an osmoregulatory hormone in teleosts and is considered to be of more importance in fresh water (FW) than in seawater (SW) (Hirano and Mayer-Gostan, 1978;Loretz and Bern, 1982;Prunet et al, 1985;Hirano, 1986). Stress is known to cause hydromineral imbalance (Mazeaud et al, 1977;Eddy, 1981) and concomitant elevation in the concentration of the stress hormone cortisol (Mazeaud et al, 1977;Donaldson, 1981;Schreck, 1981).…”

Changes in the expression of neurohypophyseal prolactins during the estrous cycle and after estrogen treatment

“…In this regard, PRLs were found to be released from neurohypophyseal endings in response to high potassium and the 14 kDa variant was found in the circulation (Torner et al 1995). Moreover the kidney is a well-known target of neurohypophyseal hormones and of PRL (Hebert et al 1981, Loretz & Bern 1982 and PRL fragments have been shown to bind to renal PRL receptors with higher affinity than PRL itself (Clapp et al 1989).…”

Variations horaires de la température rectale et de la prolactinémie chez le « Cabrit créole » maintenu à l'extérieur en milieu tropical

“…Le « cabrit créole » des Antilles Françaises (Chemineau et a/., 1983) a été utilisé dans cette étude pour préciser si cet animal est sensible à son environnement thermique alors qu'il est maintenu à l'extérieur toute la journée « au piquet », mode d'élevage traditionnel dans l'Arc Antillais (Devendra, 1971). En (Loretz et Bern, 1982 . Les Sadhu, 1961 ;Yousef, Kibler et Johnson, 1967).…”