الفهرس 
Anatomical aspects of the maleOnly 14 pages are availabe for public view
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Abstract
Cadmium (Cd) is an important heavy metal widely used in batteries, metal plating, pigments, and in the plastic industries. In addition to occupational exposure, environmental Cd exposure in humans may occur through cigarette smoking and dietary consumption.
Cadmium is a toxic metal which promotes oxidative stress and contributes to the development of serious degenerative changes in several tissues. It is well known that testes are very sensitive to acute Cd toxicity.Severe testicular hemorrhage, edema, and necrosis with destruction of seminiferous tubules are the main testicular lesions due to Cd injection.Various mechanisms have been suggested to explain Cd-induced cellular toxicity. Oxidative stress and inflammation are the main factors implicated in cadmium induced tissue injury.
Several antioxidants and anti-inflammatory agents were found to be effective in minimizing cadmium-induced organ damage, including the testes with restoration of testicular steroidogenesis.
L-carnitine is a small water-soluble molecule important in mammalian fat metabolism. The highest concentrations of carnitine are found in red meat and dairy products. Other natural sources of carnitine include nuts and seeds (e.g. sunflower, sesame), vegetables (broccoli, garlic, mustard greens, okra), fruits (apricots, bananas), cereals (corn, oatmeal, rice bran, whole wheat, wheat bran, wheat germ) and may be found in energy drinks and various other products. Carnitines have a protective role against reactive oxygen species (ROS) by exerting antioxidant properties .Reactive oxygen species enhance lipid peroxidation, alter antioxidant system, induce DNA damage, and alter gene expression and apoptosis.
The use of L-carnitine and its derivatives in therapy has been proposed in recent years for treatment of male infertility, and a number of human and animal studies have been published that indicate a possible role for application of carnitine.
The objective of the present study was to demonstrate the effect of acute and chronic Cadmium exposure on testis of adult male albino rats and the possible protective role of L-carnitine on Cadmium induced testicular damage.
This work was performed on 50 adult male albino rats.
- The animals were divided as follow:-
(1) Control group (Group I) (10 animals): This group was treated with 9% normal saline by intra peritoneal injection daily.
(2) Experimental group (Group II) (40 animals):
This group was subdivided into:
A)Acute group: which was subdivided into:
Subgroup A1: (10 animals):
Rats were given a single intra peritoneal injection of Cadmium cholride in a dose of 2.5 mg/ kg .
Subgroup A2: (10 animals)
Rats were given L-carnitine and Cadmium cholride in a dose of 200 mg/kg and 2.5mg/kg intraperitoneal injection respectively.Cadmium cholride was given as single injection and L-carnitine injection was started one day before and continued for two dayes after Cadmium adminisrtation was stopped.
B)Chronic group:which was subdivided into:
Subgroup B1: (10 animals):
Rats were given Cadmium cholride in a dose of 1mg/kg by intraperitoneal injection for four weeks with an interval of 48 h between subsequent injections.
Subgroup B2: (10 animals):
Rats were given L-carnitine and Cadmium cholride in a dose of 200mg/kg and 1mg/kg intra peritoneal injection respectively.Cadmium cholride was given for four weeks with an interval of 48 h between subsequent injections and L-carnitine injection was started one day before and continued for two dayes after Cadmium adminisrtation with the same interval .
By the end of the experiment the animals were anesthetized , sacrificed and from each animal the two testes were taken and divided transversely into 2 halves. One half was processed for paraffin sections for L/M examination and the other half was processed for E/M examination.
- Testicular tissue samples were stained with hemotoxylin and eosin and Masson’s trichrome for histological evaluation.
- Tissue sections were examined by transmission electron microscope (T.E.M).
Histological examination of testicular tissue structure of adult rabbits revealed the following results:
Control group (Group 1) showed normal structure of testis, S.Ts., spermatogenic cells, sperms, Sertoli cells, Leydig cells, myoid cells and B.M of S.Ts.
Acute cadmium group (Group II A1 ) showed sever inflammation,vaculation and degeneration of S.Ts, shedding of their germinal epithelium .The interstitium show marked edema ,inflammation and congestion.Microtubular structure of sperms didn’t change but their number decrease.
Acute cadmium plus L-carnitine group(Group II A2) showed improvement of testicular tissue structure. Most S.Ts. were apparently regular in shape and size. There was normal spermatogenic cells, sperms, Sertoli cells, Leydig cells & B.M. of S.Ts. was thin & regular.The vacuolations in group II A1 disappeared and the cytoplasm of all cells returned to near normal.Spermatic count apparently increased.
Chronic cadmium group(Group II B1) showed marked affection of the testicular tissue structure.S.T.s were destructed,atrophic and vaculated, the cytoplasm of spermatogenic cells, Sertoli cells and Leydig cells showed. marked vacuolation (few organelles & fragmented mitochondria & multiple vacuoles of large sizes) with thickeneing and irregularity of the B.M. Interstitial fibrosis was abserved.Loss of microtubular structure of sperms.
Chronic cadmium plus L-carnitine group (Group II B2) showed mild improvement in size of S.T.s. appearance of some sperms in the lumen of S.Ts. .B.M was thick regular. I.T showed decreased fibrosis . Spermatid with acrosomal vesicle and cap appeared and some T.S of sperms showed appearance of microtubular structure but with apparently deacreased spermatic population.
In conclusion, In the present study the use of L-carnitine before and during administration of cadmium showed marked reduction in the testicular toxic effect of acute cadmium exposure and mild improvement in the testicular toxic effect of chronic cadmium exposure which appeared in improvement of cadmium induced pathological changes on the testis detected by light and electron microscopic examination.
So L-carnitine can be considered as a protective agent against cadmium testicular toxicity.