[Synthesis and activities of fragments of inhibin alpha subunit].

For further investigation of inhibin which is available only by laborious isolation, four fragments of inhibin alpha subunit (7-28, 37-65, 1-32, Y-1-32) were prepared by solid phase peptide synthesis using the Fmoc strategy. The effects of these fragments on progesterone production of rat corpus luteal (CL) cells in vitro were examined. The results indicate that these four fragments induced significant decrease of basic progesterone production.

[Implantations of posterior chamber intraocular lenses in children with monocular cataracts].

Extracapsular cataract extractions with posterior chamber intraocular lens implantations were performed on 43 eyes with monocular cataracts in children including 35 cases of traumatic and 8 cases of congenital cataracts. 65.7% of eyes with traumatic cataracts and 25% of eyes with congenital cataracts achieved postoperative corrected visual acuities of > or = 0.5. It has been found that children have good tolerance to posterior chamber intraocular lens and no serious ocular complications, such as persistent uveitis, bullous keratopathy, or secondary glaucoma were seen. The main factors influencing the visual acuity are opacification of the posterior lens capsule and amblyopia. Their methods of prevention and treatment were discussed.

[Effect of gonadotropin-releasing peptide (GRP) on LH secretion of mouse pituitary in vitro].

Synthetic GRP and its analogues, GRP-NH2, [Glu7.9.14 Lys6.10] GRP (6-14), [Phe14] GRP (5-14) and [Phe14] GRP, at the concentration of 0.05 mmol.L-1 were shown to have stimulatory effect on LH secretion in cultured mouse pituitary in vitro. The luteotropin releasing activity of GRP and its analogues was estimated to be 115.4, 114.2, 140.0, 162.0 and 179.0% of the control group, respectively. Subcutaneous administration of [Phe14] GRP on days 7-9 and 1-5 of pregnancy and [Phe14] GRP (5-14) on days 2-4 of gestation at dosage of 1 mg.d-1 (each mouse) caused fetal death in 40-60% of mice.

[Intraocular lens implantation in high myopes].

36 highly myopic eyes were done extracapsular cataract extraction with posterior chamber IOL implantation and followed up 12-77 months, averaging 33 months. 95% of the patients with ocular axial lengths of 26 to 28 mm achieved corrected visual acuities of 0.5 or over, whereas for eyes with axial lengths over 28 mm, the visual prognosis was less satisfactory. There had been no complications of retinal detachment, glaucoma or corneal dystrophy.

[Synthesis of small peptides containing hydroxy-amino-acid, and its effects on progesterone production].

Eleven peptides containing hydroxy-amino-acid have been synthesized manually by stepwise solid-phase method. Three of them were started on BHA-resin, the others on Merrifield-resin. TFMSA/TFA/p-cresol were used as cleaving reagent in all peptide-resin (1-11) cleavage. Furthermore, HF cleaving procedure was also used parallelly to five of those peptide-resins for contrast. No conspicuous difference in yield was found between TFMSA and HF. The purity of all products was checked by the profiles of analytical reversed phase HPLC (C-18) and the data of amino acid analysis. All synthetic peptides were tested for the effect on progesterone production by rat corpus luteum in vitro. Among them, three peptides, GlyTyr-NH2, LysTyr-NH2 and GlySer Lys-OH, showed significant effect (p less than 0.01) on inhibiting hCG-induced progesterone production.

Synthesis and hormonal activity of [Tyr22] glucagon and [desHis1, Tyr22] glucagon.

[Tyr22] glucagon and [desHis1, Tyr22] glucagon were synthesized by an improved solid phase procedure on a Pam-resin. The course of the synthesis was monitored by quantitative ninhydrin analysis and preview sequencing. Following cleavage by the low/high HF method the peptides were purified by ion exchange chromatography and reverse phase HPLC. The overall yield of homogeneous isolated peptide from the first amino acid was 41%. Circular dichroism measurements on dilute solutions in mixed aqueous organic solvents at pH 2, 6.9 and 9.2 showed increased beta-sheet structure relative to glucagon. [Tyr22] glucagon was a full agonist with 20-30% activity in the rabbit blood glucose assay and 10% activity in the rat liver membrane adenyl cyclase assay. [desHis1, Tyr22] glucagon had only a trace of activity in the adenyl cyclase assay (less than 0.002%) but bound to membranes in a competitive [125I] glucagon assay 1.0% as well as glucagon. The analog completely inhibited formation of cAMP by natural glucagon, with 50% inhibition at a ratio of 83:1 and pA2 = 6.7. The data are discussed in terms of models of glucagon structure in dilute solution.