Copyright Notice:  Copyright (C) Newman K. Lin, Ph.D., PE., The Lin Institute, All rights reserved. If you want to use the information of this document, Please contact Dr. Lin by e-mail: Lin_Institute@yahoo.com
Case Study:  Penile sensitivity, erection, semen retention and prostate pains
Reader: 8/19/2010>
Dear Dr Lin,
I read in taoist literature and experienced sensually that the penis during intercourse and masturbation is less sensitive to applied pressure than it is to friction and that for the vagina it is the other way around. Is it possible to increase staying power of the penis ie. time of intercourse/masturbation before ejaculation by training the penis to handle more pressure. Does this kind of training over time decrease penile sensitivity to friction? Is it true that the most sensitive area of the penis is where the inner foreskin joins onto the outer foreskin? Finally I am 42 and have been practicing ejaculatory restraint since the age of 25. This means I have only ejaculated between 2-6 times a year. Some of these ejaculations were the results of nocturnal emissions some due to love making. In the last few years I have noticed a sharp pain in my prostrate when ejaculating obviously because the prostate is too full. Is it damaging for the prostate if it does not contract/convulse in ejaculation regularly? Thank you in advance for your answer
Dr. Lin: 8/19/2010> Androgen hormones and  neurotransmitters dopamine/acetylcholine/NO/oxytocin/norepinpehrine are the main factors affecting the penile sensitivity and erectile power.
Prostaglandin E2 and histamine are the other factors increasing the penile erection and sensitivity that may lead to premature ejaculation.
Prostaglandins E1/E3 and endorphin can reduce the penile sensitivity for lasting longer, but improve erection.
Prostaglandin D2 can heat up the skin and penis for erection and penile sensitivity, but at a high level it can trigger histamine release for premature ejaculation. If it works with serotonin and GABA, it helps both erection/sensitivity and prevent premature ejaculation.
You can not train your penis, but you can try to stimulate the L1 and L2  nervous reflex arc with  prostate/PC muscle exercises to release more prostaglandin E2 and DHT that improve your erection and orgasm response and promote ejaculation faster.
The most penile sensitive area is called the triggering zone, under your glans penis and about 1 inch from the urethral orifice, like the female G-spot location, as shown in
http://action.love/love/trigger.htm
or
http://www.actiontao.com/image/enlarge.jpg
Semen/sperm retention is as bad as over-ejaculation.
I have explained this problem in:
Non-orgasmic semen retention is as bad as over-ejaculation; both are for no more sexual orgasm ,but for sympathetic nervous pains and burning. What is different between both cases in term of the dopamine-norepinephrine-epinephrine conversion?
==> http://action.love/cases/case13176.htm
On seminal retention and prostate-cancer protection, and of course, on Over-masturbation and sexual orgasm
==> http://action.love/cases/case11407.htm or
http://action.love/extra/vascectomy.htm  

Excessive prostaglandin E2, testosterone, DHT and norepinephrine, epinephrine and oxytcoin in semen will hyper-activate the sympathetic nerves L1 and L2 and vagal nerves for anxiety, short temper and sleeping disorder in addition to the inflammatory/expansive (congestive) pain in the seminal vesicles, prostate, perineum and tailbone.
Excessive sperm accumulation inside the testicles will block the release of activin and inhibin from the testicles, both of which are supposed to unlock the hypothalamus-pituitary-testicular axis for androgen hormones and sperm production. That is, sperm retention will slow down the testosterone release at about 40% less, as vasectomized men have experienced. This testosterone drop will kill male sexual performance, penile sensitivity and erectile power for men whose pre-vasectomy (or pre-retention) testosterone level is below 800 ng/dl, since men requires a testosterone level above 500 ng/dl to have a healthy sex life.  Generally, It will take about 2-4 days for a normal 40-year old man to peak his testosterone to reach 600-700 nd/dl again after last ejaculation. If he practices sperm retention, his testosterone level will drop down to 400-500 nd/dl after 7-10 days and he will experience the sympathetic nervous Flight and Fight : having some difficulties to have a hard erection for sex and also experiencing  premature ejaculation once he has sex encounter.

Reader: 8/24/2010>
Dear Dr Lin, Thank you for answering my query so promptly and masterfully. I feel you have a real and rare genius for matters that relate to love erotic physiology and practice. I would like to ask you about a strange physical phenomenon. Even my doctor does not know why this is so maybe you can help. Most of the time in the waking state (conscious) I draw up the muscles around my sphincter also other inner muscles of my pelvic floor. This is similar to trying to hold back bowel movement. The first time I became aware of this was when I was about 6 years old. It gets more intense when I experience stress or vigilance concentration etc. It almost seems that this contracted state is the natural state for me not a state in which the muscles are relaxed. If I am not aware hours can pass before I notice this and relax the muscles. By which time my lower abdomen ie intenstines also seem contracted and feel cramped up. Is this an inner tension? Does it have a cause in sexual anatomy ie genitals! prostate anus? Or is the cause to be found more in the digestive system as the reason for the tension is the alimentary canal? Thank you for even just reading the above kind regards
Dr. Lin: 8/24/2010>
 These problems are similar to the PMS cramps and IBS.
It is due to excessive norepinephrine or deficiency of cholinergic, serotonin and GABA nervous control.
Banana are very good for the digestive dopamine and serotonin nervous control. Massaging the belly can stimulate the vagal/cholinergic nervous function.
Our products ViaPal-hGH-E(3-011) is very effective for these problems. http://action.love/mail/herbform.htm