Changes in oxytocin content in the magnocellular neurons of the rat hypothalamus following water deprivation or estrogen treatment

Rhodes, C. H.; Morrell, J. I.; Pfaff, Donald W.

doi:10.1007/bf00234544

Cited by 49 publications

(15 citation statements)

References 11 publications

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“…There are some discre pancies, however, between our results and those seen by Rhodes et al [40] using immunohistological techniques. They found relatively less staining of the OT-containing cells in the ACN of day 22 pregnant and day 5 nursing ani mals than in OVXed animals.…”

Section: Discussioncontrasting

confidence: 57%

“…Unfortunately. Rhodes et al [40] did not test animals earlier in pregnancy when we found significantly elevated OT levels. That immunohisto chemical techniques found less staining of OT-containing cells from pregnant than OVXed animals while immunore active levels of extracts from punches of the ACN found about the same or slightly more OT might indicate that the RIA technique is detecting more OT during pregnancy.…”

Section: Discussionmentioning

confidence: 96%

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Oxytocin and Vasopressin Immunoreactivity in Hypothalamic and Extrahypothalamic Sites in Late Pregnant and Postpartum Rats

et al. 1987

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This study examines immunoreactive levels of oxytocin (OT) and arginine-vasopressin (AVP) from acid extracts of the paraventricular nucleus (PVN), supraoptic nucleus (SON), anterior commissural nucleus (ACN) and the suprachiasmatic nucleus (SCN) as well as selected extrahypothalamic sites in pregnant or postpartum (PP) rats. Animals are sacrificed between 08.30 and 10.30 h 16 or 22 days after sperm is detected in their vaginal smears or on the morning after parturition. Peptide levels of pregnant or PP animals are compared to levels of ovariectomized (OVXed) rats sacrificed and assayed simultaneously. OT immunoreactive levels in the PVN and SON are significantly elevated in late pregnancy and PP. OT content of the ACN is elevated on day 16, but drops to control levels by day 22 of pregnancy and day 1 PP. Concomitant with the falling OT content in the ACN at the end of pregnancy, samples from the ventral septum have significantly increased OT content on day 1 PP. In extracts including the nucleus of the tractus solitarius (NTS) and dorsal motor nucleus of the vagus (dMX) OT is also elevated on the day after parturition. AVP levels peak on the day before parturition in all hypothalamic nuclei examined. These increases are significantly greater than in OVXed controls in the PVN and SON. AVP levels in the lateral habenula are elevated both on day 16 of pregnancy and on the first day PP. From these data we conclude that nonapeptide levels are altered across late pregnancy and early postpartum in some hypothalamic synthesis sites and in certain limbic and brainstem sites. We also postulate that OT is transported out of the ACN to extrahypothalamic sites around the time of parturition.

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Section: Discussioncontrasting

confidence: 57%

Section: Discussionmentioning

confidence: 96%

Oxytocin and Vasopressin Immunoreactivity in Hypothalamic and Extrahypothalamic Sites in Late Pregnant and Postpartum Rats

et al. 1987

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“…[49][50][51][52][53][54][55][56][57] Furthermore, recent studies have provided evidence of a gonadal steroid modulatory role on OT synthesis in the hypothalamus and of gonadal steroid induction of OT receptors in the anterior pituitary (see chapters by Brooks, Johnson, Pfaff et al, and Schumacher et al). 13 An important consideration is whether or not the OT secretory activity in the median eminence alters with the dynamic changes of the plasma level of gonadal steroids during the reproductive cycle.…”

Section: Plasma Oxytocin Release During Reproductive Cyclementioning

confidence: 99%

Pituitary Portal Plasma Levels of Oxytocin during the Estrous Cycle, Lactation, and Hyperprolactinemia

Sarkar

Frautschy

Mitsugi

1992

Annals of the New York Academy of Sciences

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Section: Introductionmentioning

confidence: 99%

“…Oxytocinergic cells in the LSN showed increased immunostaining after short-term treatment with silastic implants of estrogen (6), but decreased immunostaining after lower levels of estrogen in ovariectomized (OVX) rats (7). Longer term estrogen treatment (at least a month) also resulted in decreased OXT immunostaining in the anterior commissural nucleus (ACN), a collection of oxytocinergic cells caudal to the LSN and rostral to the PVN (6,8).Although estrogen has been shown to influence a number of OXT physiological functions, and is required for the reproductive behavioral effects of OXT (9-13), the effects of estrogen on OXT gene expression have been elusive. Van To1 el al.…”

mentioning

confidence: 99%

Estrogen Alters Oxytocin mRNA Levels in the Preoptic Area

Caldwell

Brooks

Jirikowski

et al. 1989

J Neuroendocrinology

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Estrogen has numerous effects on immunoreactive levels of oxytocin (OXT) centrally, particularly in the preoptic lateral subcommissural nucleus (LSN). In this study in situ hybridization of a 38-base oligodeoxyribonucleotide (38mer) complementary to OXT mRNA revealed that estrogen treatment altered the pattern of OXT production in the rostral LSN and the more caudal anterior commissural nucleus. Rats were injected with 20 pg estradiol benzoate or sesame oil vehicle im 4 and 5 days after ovariectomy. On the sixth day all animals were perfused with paraformaldehyde-glutaraldehyde and their brains sectioned to 10 pm thickness in a -10 "C cryostat. Coronal brain sections were taken from four parallel levels of the preoptic-anterior hypothalamic area. These sections were mounted and hybridized insifu to a [1'25]-labeled 38mer for 16 h at 37 "C. Washed and dried slides were processed for autoradiography and analyzed with a light microscope. The effect of estrogen on OXT production differed between the rostral and caudal sections in both the LSN and periventricular (PeV) areas. Estrogen significantly increased OXT mRNA levels in LSN cells while decreasing hybridization in the anterior commissural nucleus cells. Changes in frequency patterns in the PeV paralleled those in the LSN with a significant drop of hybridization in the caudal PeV. Neurons hybridizing 38mer probe were also found in several other areas including the ventral medial preoptic area, lateral hypothalamus, bed nucleus of the stria terminalis and the nucleus triangularis septi. OXT mRNA levels were affected by estrogen treatments and this effect differed between the preoptic area and anterior hypothalamus. The sensitivity of LSN oxytocinergic cells to estrogen has implications for estrogen-sensitive OXT-enhanced reproductive behaviorsThe ovarian steroid estrogen influences oxytocin (OXT) physiology in the CNS. Estrogen treatments increase OXT release from Ihe posterior pituitary (1) and increase firing of oxytocinergic neurons in the paraventricular nucleus (PVN) (2). Levels of immunoreactive OXT in the PVN vary with estrous state in ways {hat suggest estrogen's influence (3). OXT immunoreactive levels :tho increase in the PVN and supraoptic nucleus (SON) peripar-I um as estrogen levels increase, while OXT levels in more rostral synthesis sites are decreasing (4).The preoptic area (POA) sites of OXT synthesis are particularly sensitive to estrogen influence. Estrogen implants increased OXT immunoreactive content in the POA (5). Short-term treatment with silastic implants of estradiol increased the number of OXT i~nmunostained cells in the periventricular (PeV) and dorsolateral I' OA as well as in several other sites (6). The collection of oxytocinergic cells ventrolateral of the anterior commissure in the dorsolateral POA and overlapping the septohypothalamic nucleus and bed nucleus of the stria terminalis (BnST) has been called the lateral subcommissural nucleus (LSN) (6, 7). Oxytocinergic cells in the LSN showed increased immunostaining after s...

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Changes in oxytocin content in the magnocellular neurons of the rat hypothalamus following water deprivation or estrogen treatment

Cited by 49 publications

References 11 publications

Oxytocin and Vasopressin Immunoreactivity in Hypothalamic and Extrahypothalamic Sites in Late Pregnant and Postpartum Rats

Oxytocin and Vasopressin Immunoreactivity in Hypothalamic and Extrahypothalamic Sites in Late Pregnant and Postpartum Rats

Pituitary Portal Plasma Levels of Oxytocin during the Estrous Cycle, Lactation, and Hyperprolactinemia

Estrogen Alters Oxytocin mRNA Levels in the Preoptic Area

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