112
BRIAN POOLE
level of urinary constituents in the blood is elevated (Hinman, 1923), and
if half of the remaining kidney is removed this effect is prolonged for at
least 3 months (Brunner et al., 1960).
Β. Factors Modifying the Hypertrophic Response
There are many factors which affect the equilibrium kidney size. Animals
on high protein diets have enlarged kidneys (Anderson, 1926; Drummond,
1925; Miller, 1925; Osborne et al, 1927), and the rate of hypertrophy
following unilateral nephrectomy is increased (Allen and Mann, 1935;
L. L. MacKay et al, 1938; Smith and Moise, 1927), especially in older
rats. L. L. MacKay et al. (1931) found a linear relationship between protein
intake and the ratio of kidney weight to body surface in rats. The effect of
protein can be reduced or eliminated by feeding yeast extract (Longwell
et al, 1936) or vitamin Β (Ε. M. MacKay, 1933). Equivalent nitrogen in
the form of urea has a much smaller effect than protein on kidney size
(L. L. MacKay et al., 1931; Osborne et al., 1927). Kidney denervation or
decapsulation results in a very small increase in kidney size, but does not
affect the process of hypertrophy following unilateral nephrectomy (Allen
and Mann, 1935; Hix, 1963; Maluf, 1949). Partial hepatectomy has been
reported to increase the rate of kidney hypertrophy following unilateral
nephrectomy (Paschkis et al., 1959).
Previous hypophysectomy inhibits the hypertrophic response to unilateral nephrectomy in the remaining dog kidney (Astarabadi and Essex,
1953; Winternitz and Waters, 1940) and reduces the response in rat
kidney (Astarabadi and Essex, 1953; Braun-Menendez and Houssay,
1949; Colonge, 1944; McQueen-Williams and Thompson, 1940). However,
when the two operations are performed simultaneously, there is no effect
on kidney hypertrophy in rats (Rolf and White, 1953). Fontaine and Veil
(1947) found that after hypophysectomy the kidneys of rats regressed, and,
after a correction for this regression had been applied, the rate of hypertrophy following unilateral nephrectomy was normal. Astarabadi (1963b)
found a stimulatory effect of pituitary extract on kidney hypertrophy in
rats which could only partly be accounted for by the action of growth
hormone. Lactogenic hormone and ACTH have no effect. He concluded
that some other pituitary secretion was involved in the stimulation.
Thyroidectomy has been reported to have a slightly inhibitory effect on
kidney hypertrophy (Zeckwer, 1946), but thyroxine injections reportedly
do not affect the rate of hypertrophy (Rolf and White, 1953). It is reported
that neither castration nor testosterone injections increase the rate of
compensatory kidney hypertrophy (Ε. M. MacKay, 1940). Adrenalectomy
has no effect on kidney hypertrophy (Astarabadi, 1963a; G. E. G. Williams,
1962b), but cortisone injections have been reported to reduce the mitotic
index in the hypertrophying kidney (Goss and Rankin, 1960).
BRIAN POOLE
level of urinary constituents in the blood is elevated (Hinman, 1923), and
if half of the remaining kidney is removed this effect is prolonged for at
least 3 months (Brunner et al., 1960).
Β. Factors Modifying the Hypertrophic Response
There are many factors which affect the equilibrium kidney size. Animals
on high protein diets have enlarged kidneys (Anderson, 1926; Drummond,
1925; Miller, 1925; Osborne et al, 1927), and the rate of hypertrophy
following unilateral nephrectomy is increased (Allen and Mann, 1935;
L. L. MacKay et al, 1938; Smith and Moise, 1927), especially in older
rats. L. L. MacKay et al. (1931) found a linear relationship between protein
intake and the ratio of kidney weight to body surface in rats. The effect of
protein can be reduced or eliminated by feeding yeast extract (Longwell
et al, 1936) or vitamin Β (Ε. M. MacKay, 1933). Equivalent nitrogen in
the form of urea has a much smaller effect than protein on kidney size
(L. L. MacKay et al., 1931; Osborne et al., 1927). Kidney denervation or
decapsulation results in a very small increase in kidney size, but does not
affect the process of hypertrophy following unilateral nephrectomy (Allen
and Mann, 1935; Hix, 1963; Maluf, 1949). Partial hepatectomy has been
reported to increase the rate of kidney hypertrophy following unilateral
nephrectomy (Paschkis et al., 1959).
Previous hypophysectomy inhibits the hypertrophic response to unilateral nephrectomy in the remaining dog kidney (Astarabadi and Essex,
1953; Winternitz and Waters, 1940) and reduces the response in rat
kidney (Astarabadi and Essex, 1953; Braun-Menendez and Houssay,
1949; Colonge, 1944; McQueen-Williams and Thompson, 1940). However,
when the two operations are performed simultaneously, there is no effect
on kidney hypertrophy in rats (Rolf and White, 1953). Fontaine and Veil
(1947) found that after hypophysectomy the kidneys of rats regressed, and,
after a correction for this regression had been applied, the rate of hypertrophy following unilateral nephrectomy was normal. Astarabadi (1963b)
found a stimulatory effect of pituitary extract on kidney hypertrophy in
rats which could only partly be accounted for by the action of growth
hormone. Lactogenic hormone and ACTH have no effect. He concluded
that some other pituitary secretion was involved in the stimulation.
Thyroidectomy has been reported to have a slightly inhibitory effect on
kidney hypertrophy (Zeckwer, 1946), but thyroxine injections reportedly
do not affect the rate of hypertrophy (Rolf and White, 1953). It is reported
that neither castration nor testosterone injections increase the rate of
compensatory kidney hypertrophy (Ε. M. MacKay, 1940). Adrenalectomy
has no effect on kidney hypertrophy (Astarabadi, 1963a; G. E. G. Williams,
1962b), but cortisone injections have been reported to reduce the mitotic
index in the hypertrophying kidney (Goss and Rankin, 1960).