Electrolyte and hormonal effects of deoxycorticosterone acetate in young pigs.

Abstract

SUMMARY Balances of sodium, potassium, and water were studied in the growing male pig as hypertension developed in response to subcutaneous implantation of deoxycorticosterone acetate (DOCA). Serum sodium, potassium, deoxycorticosterone (DOC), aldosterone, and plasma renln actirity (PRA) were determined. These variables were observed in a total of 10 experimental and nine control pigs. All animals were uninephrectomized and fed a diet of Purina Pig Chow and tap water ad libitum. No salt was added to the food or water. Serum DOC levels rose dramatically on the day of the implantation, then gradually declined but remained approximately 10 times greater than control levels 40 days after Implant.Plasma renln activity was suppressed rapidly and completely, whereas aldosterone fell only slowly to about half its control value. Sodium retention was maximum during the first 24 hours. Thereafter an "escape" process became operative, causing sodium balance to return to normal after the third day, at which time the major rise in arterial pressure occurred. A marked increase in water turnover (intake and output) also began after the third day and persisted throughout the experimental period. Water balance remained normal during this period of increased turnover. Hypokalemia developed in the absence of kaliuresis, suggesting that potassium moved Into the cells. Except for the potassium retention, these changes parallel the abnormalities seen in other states of mineralocorticoid excess. • * Despite the large number of studies performed upon these experimental models, the pathogenesis of hypertension remains controversial.We have developed an animal model for mineralocorticoid hypertension using deoxycorticosterone acetate (DOCA) implantation in pigs, which offers several advantages for the study of hypertension. These include the rapid and highly reproducible elevation in blood pressure and the relatively large size of the animal, which allows for accurate hemodynamic measurements." In this report we describe the electrolyte and hormonal changes seen during the development of DOCA hypertension in pigs.

The relationship between oxidative stress markers and visual evoked potentials in different hypertension models

“…Therefore, the changes in different parameters among groups were not related with blood pressure or the duration of hypertension. Increased water turnover was described in some of the earliest reports of experimental DOCA hypertension (22). Our study confirms the report of Allan et al (23) who reported that DOCA treated animals consumed more water, on the other hand L-NAME group also had increased water consumption without a significant change in food consumptions.…”

The mislabelling of deoxycorticosterone: making sense of corticosteroid structure and function

“…The assumption appears to be that in vivo the acetate is rapidly hydrolysed by non-specific esterases to the free alcohol, and hence it is the latter that binds to the receptor. This may well be the case, although it has not been widely verified (Grekin et al 1980). The likely sites of deacetylation and the identities of the enzymes involved would reward study.…”

Extrarenal Na + Balance, Volume, and Blood Pressure Homeostasis in Intact and Ovariectomized Deoxycorticosterone-Acetate Salt Rats

“…DOCA salt is a "prototype" model for salt-sensitive hypertension. 4 Secondary renin-angiotensin-aldosterone system suppression, 5 increased secretion of natriuretic peptides, 6 and altered pressure natriuresis 7 establish a new steady state between Na ϩ intake and Na ϩ excretion at a new blood pressure level. The kidneys escape the mineralocorticoid signal, and additional salt retention ceases, albeit with increased blood pressure.…”