Search Results

You are looking at 1 - 2 of 2 items for

  • Author: C. VELLANO x
Clear All Modify Search
Restricted access

V. MAZZI and C. VELLANO

The administration of 100 i.u. ovine prolactin to male crested newts has been shown to block spermatogenesis by producing a zone of degeneration in spermatogonia which are about to change into primary spermatocytes (Mazzi, Vellano & Toscano, 1967).

Since signs of inhibited function of adenohypophysial type II basophils, which may be regarded as producing follicle-stimulating hormone (FSH) (Mazzi, Peyrot, Anzalone & Toscano, 1966), had been observed in prolactin-treated animals, it was assumed that the antigonadal effect of prolactin was secondary to the inhibition of FSH-producing cells. To test this hypothesis, experiments involving the simultaneous injection of prolactin and FSH were carried out.

On 13 June 1967, 40 male newts in full spermatogenetic activity were divided into four groups of ten. The first group served as controls; the second group received 100–120 i.u. prolactin (ovine, NIH-P-S7) in 0·6% NaCl solution, divided into four injections of 0·1 ml. given every other day.

Restricted access

A. PEYROT, V. MAZZI, C. VELLANO and G. LODI

SUMMARY

The transplanted pituitary is able to trigger water drive in estivating hypophysectomized adult newts up to 140 days after the operation. Both in short-term (30 days) and long-term (140 days) operated animals the grafted pituitary produced significantly more prolactin than in controls. The results indicate that in the estivating crested newt prolactin production is under an inhibitory neural control and that a short feedback control is not exerted by prolactin itself on the grafted pituitary.