Prolactin Levels in Streptozotocin-Induced Diabetic Rats

Is, Kampa; Jm, Rosenberg; Sideman, M. B.; Ll, Kampa

doi:10.1055/s-2007-1012332

Cited by 15 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The induction of diabetes (STZ+) suppressed the levels of circulating prolactin, in agreement with observations made in humans and animals (43,45,58). Although sampling was only done at one time point (i.e., at the end of the 1-hr feed), it is representative of the level normally measured in nonisolated dams that have remained with their young (59).…”

Section: Discussionsupporting

confidence: 83%

“…Studies have shown increases (39)(40)(41) and decreases (42) in glucocorticoids as well as normal and decreased levels in prolactin (43)(44)(45). There also exists an interaction between glucocorticoids and prolactin (46,47): adrenalectomy increases both basal and stress-induced levels of prolactin, whereas administration of adrenocortical steroids are inhibitory.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Effects of Diabetes Mellitus on Lactation in the Rat

Lau

Sullivan

Hazelwood

1993

Experimental Biology and Medicine

View full text Add to dashboard Cite

Diabetes mellitus adversely affects the process of lactation. Although insulin administration restores lactation, the manner by which it does so is unknown. The goals of this study were to determine which phase of lactation, milk synthesis/supply (MS), and/or milk release (MR) was affected. Inasmuch as insulin, corticosterone, and prolactin, among other hormones, are involved in milk synthesis in vitro, this study investigated their probable roles in the suppression of lactation in diabetes in vivo. Diabetes was induced in rats on Day 3 postpartum with streptozotocin (50-60 mg/kg, ip). Milk synthesis/supply and milk release were indirectly monitored using body weight gain of pups during a timed-feeding period on postnatal Days 8/9 and 13/14. Plasma corticosterone, insulin, C-peptide, and prolactin were measured by radioimmunoassay in control, diabetic, and insulin-replaced diabetic animals. Insulin replacement was provided by means of an osmotic minipump implanted subcutaneously in the nape of the neck. In addition, several parameters of maternal behavior were monitored in order to determine whether diabetes affected maternal behavior and, therefore, whether such changes played a role in the alterations of lactation observed during diabetes. Diabetes significantly suppressed MS and MR. However, the decrease in MR, which was restored after partial insulin replacement, was a reflection of the reduced MS. There were no significant differences between the parameters of maternal behavior monitored in control and diabetic animals. Blood glucose in diabetic dams was significantly increased over that of controls. Although the levels of plasma glucose in the insulin-replaced groups were significantly lower than those of their uncontrolled diabetic counterparts, they also remained higher than that of controls. Corticosterone was not significantly altered after induction of diabetes. Insulin and C-peptide levels were significantly reduced in the uncontrolled diabetics; however, insulin levels were corrected in the insulin-replaced groups. Serum levels of prolactin decreased in all diabetic groups and insulin failed to restore these levels to those of control animals. In conclusion, it appears that diabetes decreases lactation through a suppressive effect on MS rather than on MR, with insulin replacement correcting for such deficiency. In addition, despite the lactogenic importance of glucocorticoids, prolactin and insulin demonstrated in vitro, lactation in vivo can be corrected without returning the levels of all three hormones to normal. The importance of another factor(s), such as normoglycemia, as essential to the observed defects, needs to be investigated.

show abstract

Section: Discussionsupporting

confidence: 83%

mentioning

confidence: 99%

Effects of Diabetes Mellitus on Lactation in the Rat

Lau

Sullivan

Hazelwood

1993

Experimental Biology and Medicine

View full text Add to dashboard Cite

show abstract

“…140 An impairment of PRL release was observed in male Sprague-Dawley rats after streptozotocin-induced diabetes. 141…”

Section: Experimental Autoimmune Diseasementioning

confidence: 99%

The Immunology of Prolactin

Berczi¹

1992

Semin Reprod Med

View full text Add to dashboard Cite

“…Such changes may involve hypothalamic regulatory peptides, some of which are known to affect food intake and glucoregulation (1)(2)(3). Hypothalamic regulatory peptide disturbances could also be associated with the impairment of pituitary function in diabetes (4)(5)(6)(7). The identification of local regulatory peptide responses to diabetes may therefore help to elucidate important hypothalamic control mechanisms.…”

mentioning

confidence: 99%

Increased Hypothalamic Neuropeptide Y Concentrations in Diabetic Rat

Williams¹,

Steel²,

Cardoso³

et al. 1988

Diabetes

View full text Add to dashboard Cite

Central and lateral hypothalamic concentrations of 10 regulatory peptides were measured by radioimmunoassay in streptozocin-induced diabetic (STZ-D) and matched control rats between 1 day and 14 wk after diabetes induction. After 2 wk, both central and lateral hypothalamic neuropeptide Y (NPY) concentrations in STZ-D rats were consistently higher than those found in control rats, with significant 30-50% increases at 4 wk in the central hypothalamus, and at 6 and 14 wk in both central and lateral hypothalamus. Immunocytochemical studies in 4- and 6-wk STZ-D animals showed the appearance of intensely NPY-positive swollen cell bodies in the supraoptic nucleus and a subjective increase in NPY staining of medial hypothalamic nerve fibers. Central hypothalamic concentrations of three other peptides were significantly greater in STZ-D animals than those in control animals at single points (neurotensin, 1 day; calcitonin gene-related peptide, 2 wk; neurokinin, 4 wk). Hypothalamic concentrations of the other six peptides examined (bombesin, galanin, neuromedin B, substance P, somatostatin, and vasoactive intestinal peptide) did not differ significantly between STZ-D and control groups at any time. However, galanin immunostaining in the supraoptic and magnocellular paraventricular nuclei was strikingly concentrated in a reduced number of distended cell bodies. Hypothalamic peptide changes in STZ-D could be related to metabolic disturbance, changes in energy and water balance, altered pituitary function, or other factors. Persistently elevated concentrations of NPY, a very potent central stimulant of eating and drinking, may mediate the hyperphagia and polydipsia characteristic of STZ-D.

show abstract

Prolactin Levels in Streptozotocin-Induced Diabetic Rats

Cited by 15 publications

References 0 publications

Effects of Diabetes Mellitus on Lactation in the Rat

Effects of Diabetes Mellitus on Lactation in the Rat

The Immunology of Prolactin

Increased Hypothalamic Neuropeptide Y Concentrations in Diabetic Rat

Contact Info

Product

Resources

About