Anterior Pituitary Cells from Brattleboro (di/di), Long-Evans and Sprague-Dawley Rats Contain Immunoreactive Arginine Vasopressin

Abstract

A radioimmunoassay specific for arginine-vasopressin (AVP) was used to establish the presence of immunoreactive (ir)-AVP in extracts of anterior pituitary glands from Sprague-Dawley (SD) and Long-Evans (LE) rats (3.05 ± 1.0 and 1.66 ±0.9 ng/gland, respectively). Lower levels of ir-AVP (0.56 ±0.26 ng/gland) were detected in anterior pituitary gland extracts from rats with hereditary diabetes insipidus (Brattleboro; di/di). The anterior pituitary gland ir-AVP from each rat strain was further characterized by reverse-phase high-performance liquid chromatography (RP-HPLC). In each case the major peak of immunoreactivity co-migrated with synthetic AVP. By peroxidase-antiperoxidase immunocytochemistry, sparsely distributed cells containing ir-AVP were localized in anterior pituitary sections. Levels of ir-AVP in primary cultures of anterior pituitary cells (from SD rats) increased from 52 ± 5 pg/10⁶ cells at 2 days in vitro to 152 ± 17 pg/10⁶ cells at 3 days; during this period 56 ± 6 pg/ml ir-AVP was secreted into the culture medium. Fewer than 1% of the cells in these cultures were immunostainable for AVP. These data indicate that the anterior pituitary gland of the Brattleboro, Long-Evans and Sprague-Dawley rat contains ir-AVP, and that there is synthesis and secretion of this peptide in primary cultures of anterior pituitary cells in vitro.

The Vasopressin-Deficient Brattleboro Rat: Lessons for the Hypothalamo–Pituitary–Adrenal Axis Regulation

“…hypertonic saline injection, forced swim, hypoglycemia, anaphylaxis, and ulcerogen cold restraint); and (3) stimuli without a change in ACTH or corticosterone (social avoidance, footshock, and ether inhalation). Although previously it had been suggested that the role of AVP in di/di rats is observed with a disturbance in the psychological response to stress (Lolait et al 1986), we were unable to associate the role of AVP in the HPA response to a single stressor type or category.…”

Comparison of Adrenocorticotropin Control in Brattleboro, Long-Evans, and Wistar Rats

“…Mezey et al [20] reported that neurons in para ventricular and supraoptic nuclei and terminals in the neural lobe of homozygous Brattleboro rats contained immunoreactive AVP and C-terminal prepressophysin (the C terminus of the AVP precursor protein) and suggested that these mutant rats could make small amounts of the normal AVP precursor. Immunoreactive AVP has also been found in ovary, adrenal gland, and anterior pituitary gland of the homozygous Brattleboro rat [18,19,22]. These results are difficult to reconcile with the AVP gene deficit in Brat tleboro rats [25].…”

Arginine Vasopressin (AVP) and AVP-Like Immunoreactivity in Peripheral Tissues

“…More recently, Lolait et al (51) have confirmed not only the presence of ir-AVP in the anterior pituitary of normal (Sprague-Dawley and Long-Evans) rats but also have detected ir-AVP in Brattleboro rat anterior pituitary, albeit at lower levels. Characterization by RPHPLC showed that the anterior pituitary ir-AVP from all of these strains coeluted with synthetic AVP.…”

“…Lolait et al (51) also demonstrated an increase over 3 days in cell and media content of ir-AVP in cultures of rat anterior pituitary cells, suggesting that anterior pituitary ir-AVP is synthesized locally rather than originating in the median eminence. There is also indirect support for local synthesis from the earlier demonstration of ir-NP in anterior pituitaries of rats (48) and monkeys (49).…”