232
J. N. BALL
G. Extraction of Fish GH
Wilhelmi (1955) showed that a highly purified crystalline growth
hormone (identified by its action on hypophysectomized killifish; Pickford, 1954a) could be prepared from pituitary glands of hake and pollack
by application of extraction procedures designed to be effective with
mammalian glands. Wilhelmi (1955) gives the procedure in detail, and
Pickford (1957) has summarized the physicochemical properties of the
material, as determined by Dr. Wilhelmi. In general terms, and as far as
this preliminary data goes, fish GH and beef GH are quite similar, but
already differences between hake GH and pollack GH are indicated.
Hake GH and beef GH have similar isoelectric points, but pollack GH,
like that of pig and horse, is a more acid protein. On the other hand,
Wilhelmi estimated the molecular weight of beef GH by ultracentrifugation as 44,W7,000 anCr that of fish GH as 22,000-.26,000. More recently,
Dr. Wilhelmi's laboratory have revised their figures for the beef GH, now
finding a molecular weight of 22,400 (Ellis et al., 1966), but revised figures are not available for the fish hormone.
H. Hypothalamic Control of Fish GH Secretion
Growth continued in hypophysectomized P. f o m s u with ectopically
transplanted pituitaries (homotransplants), but at an extremely low rate,
indicating a partial failure of GH secretion by the transplanted gland
( Ball et al., 1965) , correlated with a marked reduction of typical GH cells
in the transplants (Olivereau and Ball, 1966). Growth hormone secretion
appears to continue at a low rate from the autotransplanted pituitary in
P. lutipinnu, although not in all cases, and the matter is still being studied
(Ball, 1968). These limited data suggest that as in higher vertebrates
(McCann et d., 1968) the hypothalamus may exert a stimulatory influence on GH secretion by the fish pituitary, but much more information
will be needed to substantiate this proposition.
REFERENCES
Abramowik, A. A., Hisaw, F. L., Bettiger, F., and Papandrea, D. N. (1940). The
origin of the diabetogenic hormone in the dogfish. Biol. Bull. 78, 189-201.
Ball, J. N. (1961). On the food of the brown trout of Llyn Tegid. Proc. 2002. SOC.
London 137, 599-622.
Ball, J. N. (1962). Brood production after hypophysectomy in the viviparous teleost
MoUienesia latipinna Le Sueur. Nature 194, 787.
J. N. BALL
G. Extraction of Fish GH
Wilhelmi (1955) showed that a highly purified crystalline growth
hormone (identified by its action on hypophysectomized killifish; Pickford, 1954a) could be prepared from pituitary glands of hake and pollack
by application of extraction procedures designed to be effective with
mammalian glands. Wilhelmi (1955) gives the procedure in detail, and
Pickford (1957) has summarized the physicochemical properties of the
material, as determined by Dr. Wilhelmi. In general terms, and as far as
this preliminary data goes, fish GH and beef GH are quite similar, but
already differences between hake GH and pollack GH are indicated.
Hake GH and beef GH have similar isoelectric points, but pollack GH,
like that of pig and horse, is a more acid protein. On the other hand,
Wilhelmi estimated the molecular weight of beef GH by ultracentrifugation as 44,W7,000 anCr that of fish GH as 22,000-.26,000. More recently,
Dr. Wilhelmi's laboratory have revised their figures for the beef GH, now
finding a molecular weight of 22,400 (Ellis et al., 1966), but revised figures are not available for the fish hormone.
H. Hypothalamic Control of Fish GH Secretion
Growth continued in hypophysectomized P. f o m s u with ectopically
transplanted pituitaries (homotransplants), but at an extremely low rate,
indicating a partial failure of GH secretion by the transplanted gland
( Ball et al., 1965) , correlated with a marked reduction of typical GH cells
in the transplants (Olivereau and Ball, 1966). Growth hormone secretion
appears to continue at a low rate from the autotransplanted pituitary in
P. lutipinnu, although not in all cases, and the matter is still being studied
(Ball, 1968). These limited data suggest that as in higher vertebrates
(McCann et d., 1968) the hypothalamus may exert a stimulatory influence on GH secretion by the fish pituitary, but much more information
will be needed to substantiate this proposition.
REFERENCES
Abramowik, A. A., Hisaw, F. L., Bettiger, F., and Papandrea, D. N. (1940). The
origin of the diabetogenic hormone in the dogfish. Biol. Bull. 78, 189-201.
Ball, J. N. (1961). On the food of the brown trout of Llyn Tegid. Proc. 2002. SOC.
London 137, 599-622.
Ball, J. N. (1962). Brood production after hypophysectomy in the viviparous teleost
MoUienesia latipinna Le Sueur. Nature 194, 787.