Masahide Munemura

Calmodulin and Ca2+- and Calmodulin-Dependent Protein Kinase in Rat Anterior Pituitary Gland

Calmodulin and Ca2+‐ and calmodulin‐dependent protein kinase were identified in the rat anterior pituitary gland. The concentration of calmodulin was 1.18 ± 0.11 μg/mg protein (n = 7) in the cytosol fraction. The calmodulin of the anterior pituitary gland co‐migrated with brain calmodulin on sodium dodecyl sulfate polyacrylamide gel electrophoresis. The Ka value of the partially purified enzyme for Ca2+ was 3.3 μ.M in the presence of 0.30μ.M calmodulin. Trifluoperazine and chlorpromazine, calmodulin‐interacting agents, inhibited enzyme activity, with Ki values of 1.3 and 2.6 x 10‐5M, respectively. The enzyme was resolved into two peaks of activity, with sedimentation coefficients of 5.5 S and 16.5 S, by sucrose density gradient centrifugation. At least nine proteins were phosphorylated by the enzyme in a Ca2+‐ and calmodulin‐dependent manner. In light of these results, the possibility that calmodulin and the calmodulin‐activatable protein kinase system are involved in the mediation of the Ca2+ effect on hormone release from the anterior pituitary gland must be given consideration.

Myasthenic crisis in the puerperium: the possible importance of α-fetoprotein. Case report

The patient was a 27-ycar-old in her first pregnancy with mild systemic myasthenia gravis (Osserman classification IIA), with weakness, ptosis and diplopia since the age of 24. There was no significant gynaecological history. She was admitted at 37 weeks gestation for observation but had been in remission from 20 weeks, and had no exacerbation before delivery. In addition to anti-acetylcholine receptor (anti-AChR) antibody, she was also found to have antinuclear antibodies. The assessment of thyroid function was normal. An ultrasound examination revealed that the fetus was normally developed and arthrogryposis was not seen. Normal fetal movements were recordcd and a non-stress test (NST) showed a reactive pattern. A 3090 g male infant was born normally a t 40 weeks with Apgar scores of 9 at 1 min, the postnatal development was normal. The mother remained clinically normal for 4 days after delivery, but on day 5 she was tired and had difficulty lifting her arms. She was discharged on day 8 postpartum, because she was well able to care for her infant, but on day 13, she had generalized weakness and dyspnoea at home. O n emergency admission, intravenous injection of edrophonium chloride (2 mg) greatly improved ptosis and muscular weakness of the neck and extremities. The evo-

Massive edema of the ovary associated with hydrothorax and ascites

A 29-year-old woman with massive edema of the ovary which was grossly mistaken for neoplasia because it was associated with large volumes of both pleural effusion and ascites is described. The ovarian mass measured 10 X 10 X 8 cm and weighed 850 g. Total hysterectomy and bilateral salpingo-oophorectomy were performed. Microscopically, the ovary consisted of diffusely edematous stroma enveloping nests of hyperplastic theca cells or showing a loose myxomatous contexture. However, no endocrine activity of the ovary was demonstrated on the basis of laboratory endocrine values obtained by radioimmunoassay techniques.

The effects of A23187 and phorbol ester on the phosphorylation of proteins in rat anterior pituitary cells.

The effects of A23187 and 12-O-tetradecanoyl-phorbol-13-acetate (TPA) on the phosphorylation of proteins in normal rat anterior pituitary cells were compared. A23187 rapidly activated the phosphorylation of at least 5 proteins (45, 47, 53, 54 and 58 kDa), which reached the maximal level in 2-10 min, and decreased gradually thereafter. In contrast, TPA activated the phosphorylation of at least 6 proteins (45, 62, 64, 72, 76 and 82 kDa), which were mostly distinguished from those activated by A23187. TPA-induced response was elicited more slowly, reached a plateau after about 10 min, and was sustained thereafter. These results suggest that the protein phosphorylation stimulated by A23187 and TPA is conducted by different mechanisms.