Prospects of Developing Human Seminal Plasma Inhibin as a Male Immunocontraceptive

Effect of Active Immunization with the C‐terminal 67–94 (R‐28) Region of Human Seminal Plasma Inhibin on the Fecundity of Adult Male Rabbits

“…Rabbit, monkey, and human ejaculated spermatozoa and rat epididymal spermatozoa were washed twice in 1.5% nutrient medium HAM's F‐10, pH 7.4 (Hi‐media) (Mumbai, India) containing 1% bovine serum albumin (BSA) and suspended in the same medium at a concentration of 50 × 10 6 spermatozoa/mL. Equal volumes of the sperm suspension and R‐28‐DT antiserum or NRS (as control) were incubated for 1 hr at 37 ∘ C and examined under the microscope.…”

“…A 100 μL aliquot of 50 × 10 6 spermatozoa/mL of washed rat, rabbit, monkey, or human sperm suspension was smeared on the slide, dried, and fixed using chilled methanol for 30 min at 0 ∘ C. The slides were air‐dried and stored at −20 ∘ C for 2 days. Following this, they were overlaid with 2% non‐fat dried milk in phosphate‐buffered saline (PBS) at room temperature for 30 min, washed with PBS, and incubated with diluted R‐28‐DT antiserum (1:100) for 1 hr at 37 ∘ C. The NRS‐layered slides served as negative controls.…”

“…The fact that hSPI is a sperm‐coating antigen 2 has been used to develop an immunocontraceptive 6 for males. Following initial encouraging experiments with the native hSPI, the N‐terminal 1–17 region (R‐17) of the native protein was synthesized and conjugated to either bovine serum albumin or diphtheria toxoid and used as an immunogen.…”