Plasma renin activity in varying hydrated states in the bullfrog

Sokabe, Hirofumi; Nishimura, Hikaru; Kawabe, Kazumi; Tenmoku, Sumio; Arai, T

doi:10.1152/ajplegacy.1972.222.1.142

Cited by 25 publications

(6 citation statements)

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“…Thus, increased renin secretion would be anticipated in situations where water enters cells, for instance during hyponatraemia. Such is apparent in the experiments of Yamamoto et al (1968), Sokabe et al (1972) and Blair-West, Brook & Simpson (1972) but is denied by the findings of Newsome & Bartter (1968) and Gordon & Pawsey (1971) where however changes in renal neurogenic tone through concomitant extracellular volume expansion could have reduced the renin releasing effect of hydration. Also apparently contrary to the suggestion is the finding of Young & Rostorfer (1973) that renin is K. BLENDSTRUP AND OTHERS released in response to acute elevation in renal artery osmolarity using either hypertonic sodium, dextrose or urea.…”

Section: Discussionmentioning

confidence: 96%

Characteristics of renin release from isolated superfused glomeruli in vitro.

Blendstrup¹,

Leyssac²,

Poulsen³

et al. 1975

The Journal of Physiology

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4. At 300 C the contained juxtaglomerular cells released renin at consistent but decreasing rates over 4-6 hr. Initial release rate in 110 mm sodium, 305 m-osmole/l. solutions was 0-86 + 0-068 x 10-6 units per 100 glomeruli per 30 min (± S.E. of mean, n = 42) or 0-546 + 0 043 % of content per 30 min. In 135 mm sodium, 305 m-osmole/l. solutions, release was 2-4-fold higher (P < 0-001) and remained elevated for at least 3 hr. When related to renin content per glomerulus resting release rate in vitro was higher by at most one order of magnitude than calculated in vivo values.5. Release was augmented by gentle physical agitation of the glomeruli. 6. Release rate was inversely related to temperature. On reducing temperature from 300 C, release increased 2'6-fold at 200 C and 6-7-fold at 100 C (P < 0-001, n = 11). The response was reversible.7. 3 mm sodium cyanide plus 3 mm sodium iodoacetate caused a variable

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Section: Discussionmentioning

confidence: 96%

Characteristics of renin release from isolated superfused glomeruli in vitro.

Blendstrup¹,

Leyssac²,

Poulsen³

et al. 1975

The Journal of Physiology

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“…Based upon findings in normal animals and man the case has been put that the juxtaglomerular apparatus functions as a volume rather than as a sodium or osmoreceptor in homoeostasis (Newsome & Bartter, 1968;Gordon & Pawsey, 1971) but there are situations where the opposite clearly obtains (Blair-West, Brook & Simpson, 1972;Sokabe, Nishimura, Kawabe, Temoku & Arai, 1972). In addition, experiments such as those of Vander & Miller (1964) in which osmotic diuretics suppressed renin release, or those of Nash, Rostorfer, Bailie, Wathen & Schneider (1968) in which hyponatraemic volume expansion increased renin release, could as well be explained by changes in osmotic pressure acting directly on the juxtaglomerular cell as by changes in the composition of fluid at the macula densa or changes in renal neurogenic tone.…”

Section: Discussionmentioning

confidence: 99%

Sensitive osmometer function of juxtaglomerular cells in vitro.

Frederiksen¹,

Leyssac²,

Skinner³

1975

The Journal of Physiology

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4. The juxtaglomerular cells were four to five times more sensitive to changes in osmolarity through sucrose than sodium chloride concentration. Changes in potassium chloride concentration (7-57 mM) had little effect.5. Sodium chloride had no direct ionic effect on renin release outside its osmotic properties.6. The findings support a previous proposal that the rate of renin release in vitro relates directly to the volume of the juxtaglomerular cell. The hypothesis is developed that a similar mechanism may underlie renin secretion in vivo.

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“…The renin-angiotensin system is also considered to be important in amphibians such as frogs (Wilson 1984), and some components of it have been found in them (Grill et al 1972, Sokabe et al 1972. Bullfrog angiotensin I is thought to be physiologically inactive, similar to mammalian angiotensin I, but they both become active when converted into angiotensin II by some converting factors (Hasegawa et al 1983).…”

mentioning

confidence: 99%

Presence of angiotensin converting enzyme (ACE) activity in serum of amphibian: comparison with ACE activity of mammalian serum

Miano

Bramucci

Murri

et al. 1997

Acta Physiologica Scandinavica

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The occurrence of angiotensin converting enzyme (EC 3.4.15.1; ACE) was demonstrated for the first time in serum of newt (Triturus carnifex) and frog (Rana esculenta). The enzymatic activity was evidenced following hydrolysis of N-[3-(2-furyl) acryloyl]L-phenylalanyl glycyl glycine (FAPGG), a synthetic substrate of ACE. The serum enzyme liberated N-[3-(2-furyl) acryloyl]L-phenylalanine (FAP) from FAPGG. The properties of the amphibian serum enzymes were compared with those of swine. The amphibian serum FAPGG hydrolysing activities were inhibited by typical ACE inhibitors, captopril and lisinopril. The optimum of pH was 8.3 at 10 and 37 degrees C and the temperature optimum was 45 degrees C. The values were similar to those of swine serum. The FAPGG Michaelis-Menten constants (K(m)) at 37 degrees C of amphibian serum enzymes (0.337 mM and 0.282 mM for frog and newt, respectively) were lower than that of swine (1.305 mM), but close to human serum enzyme. The K(m) values obtained at 10 degrees C were lower than those at 37 degrees C (0.152, 0.086, and 1.029 mM for frog, newt, and swine serum, respectively). Amphibian sera hydrolysed bullfrog synthetic angiotensin I to produce angiotensin II. Captopril (50 microM) inhibited the production of angiotensin II.

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Plasma renin activity in varying hydrated states in the bullfrog

Cited by 25 publications

References 0 publications

Characteristics of renin release from isolated superfused glomeruli in vitro.

Characteristics of renin release from isolated superfused glomeruli in vitro.

Sensitive osmometer function of juxtaglomerular cells in vitro.

Presence of angiotensin converting enzyme (ACE) activity in serum of amphibian: comparison with ACE activity of mammalian serum

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