Human Contraception

**219**

**Chapter 13**

**Abstract**

**1. Introduction**

Human Contraceptives: Current

Status, Sperm Antigen Inhibitors

*Dahril Dahril, Widi Nugroho and Aulanni'am Aulanni'am*

Rapid growth of global human population has been implicating to food shortage, social problems and environmental degradation. Contraceptive devices have long been applied as a major method to reduce natality. Current application of this technology relies upon hormonal administration, condom, withdrawal and recently hormonal vaccino-contraceptive. Discoveries of antisperm proteins have been directing current researches toward developments of antisperm antibody (ASA) contraceptions. Actions of ASA are targeting antigens either on the head or on the tail of sperm. Antibodies targeting head antigens aimed at blocking gamete fusion, ZP penetration and/or acrosome reaction. Molecules working on sperm tails are aimed to block sperm motility or energy production. PCSK4 is one sperm antigen firstly expressed on the human sperm acrosome during its initial development on the round spermatid and retains on the acrosome until sperm is matured. It is known to contribute to the postcapacitational hyperactivation of sperm essential for zona penetration. Rat models injected with rabbit-anti human PCSK4 developed incompetent sperm and allowance of these male rats to fertile female rats resulted significant reduction of conception rate. Apart from antibody, synthetic inhibitors of PCSK4 have also been developed.

The world population had grown enormously during the period of 40 years since 1960 to 2000, doubled from 3 to 6.1 billion peoples [1–3]. In 2010, it became 6.9 billion and was estimated to reach 9.3 billion in 2050 or to increase by 35% from that in 2010 [2, 4, 5]. The growth seems slower after 2000 and the global population growth in the next decades until 2050 was estimated to be slower by three times

Despite a slower growth, negative impacts of high human population on environment as well as on human have been remaining high. In one hand, the need to provide more foods to feed more peoples has triggered environment degradation through the use of chemical fertilisers, practices of intensified farming and farming mechanisations, to boost the amount of yields and frequency of harvests [6]. Moreover, increased land uses for housings and agricultures have led further environment degradation in tropical regions through deforestation [7]. On the other hand, population growth along with poverty was reported to link to further

and an Insight into PCSK4

Future developments of ASA contraception are discussed.

**Keywords:** contraception, ASA, PCSK4, synthetic peptide

compared to those during the period of 1960–2000 [1–5].
